CN115296739B - SCMA-assisted fast decoding method and system for visible light communication - Google Patents

The invention provides a quick decoding method and a quick decoding system for SCMA assisted visible light communication, wherein the method comprises the following steps: the sending end carries out codebook mapping on the bit signal according to a pre-constructed specific codebook to obtain a complex signal; modulating the complex signal to convert the complex signal into a positive real signal; the receiving end demodulates the received positive real number signal, and splits the horizontal dimension of the complex number received signal according to the number of the resource blocks, so as to obtain all possible bit information of each resource block according to the splitting result; and calculating all corresponding possible superposed signals, judging all the superposed signals based on the minimum Euclidean distance criterion to obtain target superposed signals, and performing parallel decoding on each resource block according to the target superposed signals to obtain signals transmitted by each user. The SCMA assisted rapid decoding method for visible light communication provided by the invention has the advantages of low complexity and good error rate performance.

SCMA辅助可见光通信的快速译码方法及系统SCMA-assisted fast decoding method and system for visible light communication

技术领域technical field

本发明涉及无线通信技术领域，特别涉及一种SCMA辅助可见光通信的快速译码方法及系统。The invention relates to the technical field of wireless communication, in particular to a fast decoding method and system for SCMA-assisted visible light communication.

背景技术Background technique

近年来，可见光通信(Visible Light Communication, VLC）因具有免费频谱、无电磁干扰、易于使用现有照明基础设施部署以及高级别的安全性等优势，已经慢慢成为传统的基于射频（Radio Frequency, RF）通信的替代品，尤其是在室内场景的应用中。In recent years, visible light communication (Visible Light Communication, VLC) has gradually become the traditional radio frequency (Radio Frequency, RF) communication alternatives, especially in applications in indoor scenarios.

与此同时，非正交多址（Non-Orthogonal Multiple Access, NOMA）作为实现大规模机器型通信（massive Machine Type Communication, mMTC）系统的一项关键技术，在过去几年中也受到了越来越多的研究关注。NOMA背后的主要概念是使用不同的码本（CodeBooks, CBs）或功率级别，在相同的资源元素（频率或时隙）上为多个用户提供服务，此外，越来越多的研究人员选择将SCMA技术用在可见光通信系统中，以实现万物互联的重大意义。At the same time, Non-Orthogonal Multiple Access (NOMA), as a key technology to realize massive Machine Type Communication (mMTC) system, has also received more and more attention in the past few years. more research attention. The main concept behind NOMA is to serve multiple users on the same resource element (frequency or time slot) using different codebooks (CodeBooks, CBs) or power levels. In addition, more and more researchers choose to use SCMA technology is used in visible light communication systems to realize the great significance of the Internet of Everything.

然而，在拥有超大规模连接和高速率通信的6G时代，其高速传输作为可见光通信一大优势使可见光通信成为6G关键技术之一，SCMA辅助可见光通信将要面临在LED带宽受限的条件下，如何使可见光通信传输速率进一步提升的困难，即面临这如何在调制阶数更大时，快速且有效的解码的难题。由于SCMA辅助可见光通信不可避免地在接收端存在检测复杂度较高，导致接收端功耗高的问题，在面向高速通信时问题会更突出。However, in the 6G era with ultra-large-scale connections and high-speed communications, its high-speed transmission as a major advantage of visible light communication makes visible light communication one of the key technologies of 6G. SCMA-assisted visible light communication will face the condition of limited LED bandwidth. The difficulty of further increasing the transmission rate of visible light communication is the problem of how to quickly and effectively decode when the modulation order is larger. Since SCMA-assisted visible light communication inevitably has high detection complexity at the receiving end, resulting in high power consumption at the receiving end, the problem will be more prominent when facing high-speed communication.

针对VLC-SCMA接收端检测采用MPA解码算法带来的高复杂度的问题，人们提出了许多改进的MPA算法，比如有基于对数域的MPA算法、基于串行方式的MPA解码算法、基于部分码字的MPA解码算法等等降低MPA解码复杂度的算法，可以发现这些算法只是在原有的MPA解码算法的基础上作的一点改进，并没有提出一种新的有别与MPA的解码策略，这些改进的算法大多是牺牲解码准确性基础上换取算法的复杂度降低，并且也会随着用户数的增加复杂度程指数增长，性能也会越来越差。同时，也有研究者提出在SCMA系统中利用连续干扰消除技术来降低SCMA系统的解码复杂度，然而，连续干扰消除技术的弊端也是不可忽视的，首先，相对于传统的SIC接收机，NOMA中采用的SIC接收机要更复杂，要求具备更强的信号处理能力；其次，从上述过程可知，根据信号功率排的用户顺序决定了最佳的接收效果，而在实际过程中，用户的功率是不断变化的，这就要求SIC接收机不断地对用户功率进行排序；再次，从SIC结构图中可以看出，每一级处理都会产生一定的时延，在现实多级处理过程中，产生的时延很大。Aiming at the high complexity problem caused by the MPA decoding algorithm used in VLC-SCMA receiver detection, many improved MPA algorithms have been proposed, such as MPA algorithm based on logarithmic domain, MPA decoding algorithm based on serial mode, part-based The MPA decoding algorithm of the codeword and other algorithms that reduce the complexity of MPA decoding can be found that these algorithms are only a little improvement on the basis of the original MPA decoding algorithm, and a new decoding strategy that is different from MPA is not proposed. Most of these improved algorithms sacrifice decoding accuracy in exchange for reduced algorithm complexity, and as the number of users increases, the complexity will increase exponentially, and the performance will become worse and worse. At the same time, some researchers have proposed to use the continuous interference cancellation technology in the SCMA system to reduce the decoding complexity of the SCMA system. However, the disadvantages of the continuous interference cancellation technology cannot be ignored. First, compared with the traditional SIC receiver, NOMA uses The SIC receiver is more complex and requires stronger signal processing capabilities; secondly, from the above process, it can be seen that the order of users according to the signal power determines the best receiving effect, and in the actual process, the power of the users is constantly This requires the SIC receiver to continuously sort the user power; again, it can be seen from the SIC structure diagram that each level of processing will generate a certain delay. In the actual multi-level processing process, the generated time The extension is great.

因此如何设计一个针对高速通信复杂度低且不损失解码准确性的检测方法是当前面临的主要难题。Therefore, how to design a detection method for high-speed communication with low complexity and without loss of decoding accuracy is the main problem at present.

发明内容Contents of the invention

基于此，本发明的目的是提出一种SCMA辅助可见光通信的快速译码方法及系统，旨在解决现有解码算法技术中低复杂度和良好检测性能不可兼得的问题，同时本发明针对更大过载率和更高阶的VLC-SCMA系统检测具有良好的适用性。Based on this, the purpose of the present invention is to propose a fast decoding method and system for SCMA-assisted visible light communication, which aims to solve the problem that low complexity and good detection performance cannot be achieved in the existing decoding algorithm technology. At the same time, the present invention aims at more It has good applicability for large overload rate and higher order VLC-SCMA system detection.

根据本发明提出的一种SCMA辅助可见光通信的快速译码方法，所述方法包括：According to a fast decoding method for SCMA-assisted visible light communication proposed by the present invention, the method includes:

发送端获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号；The transmitting end obtains bit signals of multiple users, and performs codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain a complex signal;

将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；ACO-OFDM modulation is performed on the complex number signal to convert it into a positive real number signal, and the positive real number signal is channel-gained and then transmitted to the receiving end;

所述接收端将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号，并按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块可能存在的所有比特信息；The receiving end performs ACO-OFDM demodulation on the received positive real signal to convert the positive real signal into a complex received signal, and splits the complex received signal in a horizontal dimension according to the number of resource blocks, To obtain all possible bit information of each resource block according to the splitting result;

根据每一资源块上可能存在的所有比特信息计算出对应的所有可能的叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号。Calculate all possible superposition signals corresponding to all possible bit information on each resource block, and judge all the superposition signals based on the minimum Euclidean distance criterion, so as to obtain the target corresponding to the minimum Euclidean distance according to the judgment result Superimpose signals, and perform parallel decoding on each resource block according to the target superimposed signal, so as to obtain signals transmitted by each user.

进一步地，所述发送端获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号的步骤之前包括：Further, the transmitting end obtains bit signals of multiple users, and performs codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals, and the step of obtaining the complex signal includes :

根据实际应用场景的需求获取过载率目标值，并根据所述过载率目标值设定对应的码本大小、用户最大承载数量、资源块个数以及每个资源块过载用户数；Obtaining the target value of the overload rate according to the requirements of the actual application scenario, and setting the corresponding codebook size, the maximum number of bearers of users, the number of resource blocks, and the number of overloaded users for each resource block according to the target value of the overload rate;

将所述特定码本中的母星座结构定义为行矩阵，所述行矩阵中包括两种互为相反数的字符，并根据所述码本大小设定所述行矩阵中的字符数量；Defining the female constellation structure in the specific codebook as a row matrix, the row matrix includes two characters with opposite numbers, and setting the number of characters in the row matrix according to the size of the codebook;

根据每个资源块过载用户数对所述母星座结构进行旋转操作和功率分配，以构建得到与每个资源块对应的因子矩阵。Perform a rotation operation and power allocation on the mother constellation structure according to the number of overloaded users in each resource block, so as to construct a factor matrix corresponding to each resource block.

进一步地，所述接收端将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号的步骤包括：Further, the receiving end performs ACO-OFDM demodulation on the received positive real number signal, so that the step of converting the positive real number signal into a complex received signal includes:

根据以下公式对所述正实数信号进行接收：The positive real number signal is received according to the following formula:

Y=HX+nY=HX+n

其中，Y表示接收信号，X表示正实数信号，H表示可见光信道增益，n表示高斯噪声；Among them, Y represents the received signal, X represents the positive real number signal, H represents the visible light channel gain, and n represents Gaussian noise;

所述接收端将接收到的信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号。The receiving end performs ACO-OFDM demodulation on the received signal, so as to convert the positive real signal into a complex received signal.

进一步地，所述按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块可能存在的所有比特信息的步骤包括：Further, the step of splitting the complex received signal in the horizontal dimension according to the number of resource blocks, so as to obtain all bit information that may exist in each resource block according to the split result includes:

根据所述特定码本对所述复数接收信号进行逐位拆分，并将拆分后得到的比特信息进行码本映射，以将所述复数接收信号转换为单比特信息；Splitting the complex received signal bit by bit according to the specific codebook, and performing codebook mapping on the bit information obtained after splitting, so as to convert the complex received signal into single-bit information;

根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号；Obtain the user index occupying each resource block according to the factor matrix, so as to obtain all user numbers occupied on each resource block;

根据每个资源块上占用的所有用户号以及得到的所有单比特信息列出占用每个资源块上的各个用户可能存在的所有比特序列的组合。According to all user numbers occupied on each resource block and all obtained single-bit information, combinations of all bit sequences that may exist for each user occupying each resource block are listed.

进一步地，所述根据每一资源块上可能存在的所有比特信息计算出对应的所有可能的叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号的步骤包括：Further, all the corresponding superimposed signals are calculated according to all bit information that may exist on each resource block, and all the superimposed signals are judged based on the minimum Euclidean distance criterion, so as to obtain the minimum The target superposition signal corresponding to the Euclidean distance, and each resource block is decoded in parallel according to the target superposition signal, so as to obtain the signal transmitted by each user. The steps include:

根据各个用户可能存在的所有比特序列的组合分别计算出与所述比特序列一一对应的叠加码字，每种所述比特序列与其对应的所述叠加码字具有唯一可译原则；According to the combination of all possible bit sequences that may exist in each user, superimposed codewords corresponding to the bit sequences are calculated one by one, and each kind of bit sequence and the corresponding superimposed codewords have a unique decodable principle;

根据每一资源块可能存在的叠加码字和所述复数接收信号计算出每种叠加码字分别与所述复数接收信号的欧式距离，并从获取的所有欧式距离中筛选出最小欧式距离，以根据所述最小欧式距离锁定与其对应的目标叠加码字。Calculate the Euclidean distance between each superimposed codeword and the complex received signal according to the superimposed codewords that may exist in each resource block and the complex received signal, and select the minimum Euclidean distance from all obtained Euclidean distances to obtain The corresponding target superposition codeword is locked according to the minimum Euclidean distance.

进一步地，所述根据每一资源块上可能存在的所有比特信息计算出对应的所有可能的叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号的步骤还包括：Further, all the corresponding superimposed signals are calculated according to all bit information that may exist on each resource block, and all the superimposed signals are judged based on the minimum Euclidean distance criterion, so as to obtain the minimum The target superposition signal corresponding to the Euclidean distance, and performing parallel decoding on each resource block according to the target superposition signal, so as to obtain the signal transmitted by each user. The steps also include:

基于所述唯一可译原则获取与所述目标叠加码字对应的目标比特序列，并根据在每一资源块上分别预设的解码器对各个资源块分别对应的目标比特序列进行并行解码。The target bit sequence corresponding to the target superimposed codeword is obtained based on the unique transcodability principle, and the target bit sequence corresponding to each resource block is decoded in parallel according to a decoder preset on each resource block.

进一步地，所述根据每一资源块可能存在的叠加码字和所述复数接收信号计算出每种叠加码字分别与所述复数接收信号的欧式距离的步骤包括：Further, the step of calculating the Euclidean distance between each superimposed codeword and the complex received signal according to the superimposed codewords that may exist in each resource block and the complex received signal includes:

根据以下公式计算所述欧式距离：The Euclidean distance is calculated according to the following formula:

其中，‖•‖表示求解欧式距离，min表示检索所有欧式距离中的最小值，y_k表示所述复数接收信号中的第k维信号，s(j)表示第j组比特序列所对应映射的叠加码字，m表示解码出的目标叠加码字所在的位置，用于检索目标叠加码字。Among them, ‖‖‖ means to solve the Euclidean distance, min means to retrieve the minimum value of all Euclidean distances, y _k means the k-th dimension signal in the complex received signal, s(j) means the corresponding mapping of the jth group of bit sequences The superimposed codeword, m represents the location of the decoded target superimposed codeword, and is used to retrieve the target superimposed codeword.

进一步地，所述根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号的步骤包括：Further, the step of obtaining the user index occupying each resource block according to the factor matrix to obtain all user numbers occupied on each resource block includes:

根据以下公式进行索引：Indexed according to the following formula:

其中，U(:，k)是表示在资源块k上占用的用户号，find表示find matlab函数，F表示因子矩阵。Among them, U(:, k) represents the user number occupied on the resource block k, find represents the find matlab function, and F represents the factor matrix.

进一步地，根据以下公式获取所述复数接收信号中的第k维信号：Further, the k-th dimensional signal in the complex received signal is obtained according to the following formula:

y_k=Hx_k+ny _k =Hx _k +n

其中，x_k表示第k个资源块上df个用户的叠加信号，y_k表示复数接收信号的第k维信号，df表示第k个资源块上的用户数，H表示可见光信道增益，n表示高斯噪声。Among them, x _k represents the superimposed signal of df users on the k-th resource block, y _k represents the k-th dimension signal of the complex received signal, df represents the number of users on the k-th resource block, H represents the visible light channel gain, and n represents Gaussian noise.

根据本发明实施例的一种SCMA辅助可见光通信的快速译码系统，所述系统包括发送端和接收端，其中：A fast decoding system for SCMA-assisted visible light communication according to an embodiment of the present invention, the system includes a sending end and a receiving end, wherein:

所述发送端包括：The sender includes:

码本映射模块，用于获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号；A codebook mapping module, configured to obtain bit signals of multiple users, and perform codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain a complex signal;

信号调制模块，用于将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；A signal modulation module, configured to perform ACO-OFDM modulation on the complex signal to convert it into a positive real number signal, and transmit the positive real number signal to the receiving end after performing channel gain;

所述接收端包括：The receiver includes:

信号解调模块，用于将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号，并按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块可能存在的所有比特信息；The signal demodulation module is used to perform ACO-OFDM demodulation on the received positive real number signal, so as to convert the positive real number signal into a complex received signal, and carry out the horizontal dimension of the complex received signal according to the number of resource blocks Splitting, so as to obtain all bit information that may exist in each resource block according to the splitting result;

并行解码模块，用于根据每一资源块上可能存在的所有比特信息计算出对应的所有可能的叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号。A parallel decoding module, configured to calculate all possible superimposed signals corresponding to all possible bit information on each resource block, and judge all the superimposed signals based on the minimum Euclidean distance criterion, so as to obtain The target superposition signal corresponding to the minimum Euclidean distance, and each resource block is decoded in parallel according to the target superposition signal, so as to obtain the signal transmitted by each user.

与现有技术相比：通过特定码本结构，以对发射端的信号进行拆分，并根据码本可拆分特点，将发射端的信号和码字进行拆分重组，并对码字重组后的序列和叠加信号设置成唯一可译的特点，进而完成对接收信号的解码，具有复杂度低以及误码率性能良好的优点。具体为：发送端首先通过一全新的特定码本对多个用户的比特信号进行码本映射，进而使得比特信号实现信号叠加，得到复数信号，而后再对复数信号分别进行调制转换和信道增益，再将完成信号增益的正实数信号发送给接收端，接收端再将接收到的正实数信号进行对应的解调，而后将解调后得到的复数接收信号进行横向维度的拆分，以获取每一资源块可能存在的所有比特信息，进而根据所有的比特信息计算出可能存在的所有叠加信号，而后基于最小欧式距离准则对所有可能的叠加信号进行判决，以得到目标叠加信号，进而按照该目标叠加信号对每个资源块进行并行解码，从而解码出每个用户所发射的信号，整个解码过程较为简单，同时针对更大过载率和更高阶的VLC-SCMA系统检测具有良好的适用性。Compared with the existing technology: through a specific codebook structure, the signal at the transmitting end is split, and according to the splittable characteristics of the codebook, the signal and codeword at the transmitting end are split and reassembled, and the recombined codeword The sequence and the superimposed signal are set as the only decodable features, and then the decoding of the received signal is completed, which has the advantages of low complexity and good bit error rate performance. Specifically, the sending end first performs codebook mapping on the bit signals of multiple users through a new specific codebook, so that the bit signals can be superimposed to obtain complex signals, and then perform modulation conversion and channel gain on the complex signals respectively. Then send the positive real number signal that has completed the signal gain to the receiving end, and the receiving end will demodulate the received positive real number signal correspondingly, and then split the complex number received signal obtained after demodulation in the horizontal dimension to obtain each All the bit information that may exist in a resource block, and then calculate all the possible superimposed signals based on all the bit information, and then judge all possible superimposed signals based on the minimum Euclidean distance criterion to obtain the target superimposed signal, and then according to the target The superimposed signal decodes each resource block in parallel to decode the signal transmitted by each user. The whole decoding process is relatively simple, and it has good applicability for detection of larger overload rate and higher order VLC-SCMA system.

本发明的附加方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本发明的实施例了解到。Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be apparent from the description which follows, or may be learned by practice of the invention.

附图说明Description of drawings

图1为本发明第一实施例提出的SCMA辅助可见光通信的快速译码方法的流程图；FIG. 1 is a flowchart of a fast decoding method for SCMA-assisted visible light communication proposed in the first embodiment of the present invention;

图2为本发明第二实施例提出的SCMA辅助可见光通信的快速译码方法的流程图；FIG. 2 is a flowchart of a fast decoding method for SCMA-assisted visible light communication proposed in the second embodiment of the present invention;

图3为本发明第二实施例中的码本拆分映射解析图；FIG. 3 is an analysis diagram of codebook splitting and mapping in the second embodiment of the present invention;

图4本发明第二实施例中同一码本在150%情况下的误码率性能对比图；Fig. 4 is a comparison diagram of bit error rate performance in the case of 150% of the same codebook in the second embodiment of the present invention;

图5为本发明第三实施例提出的SCMA辅助可见光通信的快速译码系统的结构示意图。FIG. 5 is a schematic structural diagram of an SCMA-assisted fast decoding system for visible light communication proposed in a third embodiment of the present invention.

如下具体实施方式将结合上述附图进一步说明本发明。The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

具体实施方式Detailed ways

为了便于理解本发明，下面将参照相关附图对本发明进行更全面的描述。附图中给出了本发明的若干个实施例。但是，本发明可以以许多不同的形式来实现，并不限于本文所描述的实施例。相反地，提供这些实施例的目的是使对本发明的公开内容更加透彻全面。In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the associated drawings. Several embodiments of the invention are shown in the drawings. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be thorough and complete.

除非另有定义，本文所使用的所有的技术和科学术语与属于本发明的技术领域的技术人员通常理解的含义相同。本文中在本发明的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本发明。本文所使用的术语“及／或”包括一个或多个相关的所列项目的任意的和所有的组合。Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

请参阅图1，所示为本发明第一实施例中的SCMA辅助可见光通信的快速译码方法的流程图，该方法包括步骤S01至步骤S04，其中：Please refer to FIG. 1, which shows a flow chart of a fast decoding method for SCMA-assisted visible light communication in the first embodiment of the present invention, the method includes steps S01 to S04, wherein:

步骤S01：发送端获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号；Step S01: The transmitting end obtains bit signals of multiple users, and performs codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain a complex signal;

需要说明的是，特定码本是在信号传输前就已经预存在发送端和接收端中的，当发送端获取到各个用户的比特信号时，即通过该特定码本对比特信号进行映射，以使得多个比特信号进行信号叠加，进而得到该复数信号，该复数信号包括实数信号和虚数信号两部分。It should be noted that the specific codebook is pre-stored in the sending end and the receiving end before signal transmission, and when the sending end obtains the bit signals of each user, it maps the bit signals through the specific codebook, so as to Signal superposition is performed on multiple bit signals to obtain the complex signal, and the complex signal includes two parts: a real number signal and an imaginary number signal.

步骤S02：将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；Step S02: ACO-OFDM modulation is performed on the complex signal to convert it into a positive real signal, and the positive real signal is channel-gained and then transmitted to the receiving end;

可以理解的，在本步骤中，信道增益一般指的是对可见光信道的直射增益。It can be understood that in this step, the channel gain generally refers to the direct gain of the visible light channel.

步骤S03：所述接收端将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号，并按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块可能存在的所有比特信息；Step S03: The receiving end performs ACO-OFDM demodulation on the received positive real number signal to convert the positive real number signal into a complex received signal, and performs horizontal dimension of the complex received signal according to the number of resource blocks Splitting, so as to obtain all bit information that may exist in each resource block according to the splitting result;

具体的，根据以下公式对所述正实数信号进行接收：Specifically, the positive real number signal is received according to the following formula:

Y=HX+nY=HX+n

其中，Y表示接收信号，X表示正实数信号，H表示可见光信道增益，n表示高斯噪声；Among them, Y represents the received signal, X represents the positive real number signal, H represents the visible light channel gain, and n represents Gaussian noise;

所述接收端将接收到的信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号。The receiving end performs ACO-OFDM demodulation on the received signal, so as to convert the positive real signal into a complex received signal.

进一步地，为了降低解码算法的复杂度，需要将得到的复数接收信号其按资源块个数进行横向维度拆分，进而根据每个资源块维度进行解码，需要说明的是，每一资源块维度均对应多个可能存在的比特信息。Further, in order to reduce the complexity of the decoding algorithm, it is necessary to split the obtained complex received signal in the horizontal dimension according to the number of resource blocks, and then decode according to the dimension of each resource block. It should be noted that each resource block dimension Each corresponds to multiple bits of information that may exist.

步骤S04：根据每一资源块上可能存在的所有比特信息计算出对应的所有可能的叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号。Step S04: Calculate all possible superposition signals corresponding to all possible bit information on each resource block, and judge all the superposition signals based on the minimum Euclidean distance criterion, so as to obtain the minimum Euclidean distance according to the judgment result corresponding target superposition signal, and perform parallel decoding on each resource block according to the target superposition signal, so as to obtain the signal transmitted by each user.

可以理解的是，为了锁定各个资源块所对应的比特信息，首先需要根据可能存在的所有比特信息计算出该资源块上的叠加信号，该叠加信号为占用该资源块上所有用户的传输信号，进而再对该叠加信号信号进行最小欧式距离的判决，以获取到最小欧式距离所对应的目标叠加信号，需要说明的是，每个资源块均存在多个可能的比特信息，因此每个资源块对应会计算出多个叠加信号，进而锁定与该资源块吻合的目标叠加信号，再根据该目标叠加信号找出所对应的目标比特信息，以将所有资源块分别对应的目标比特信息进行并行解码，进而得到各个用户发射的信号，进而完成整个解码工作，整个解码过程复杂度较低，同时误码率较低。It can be understood that, in order to lock the bit information corresponding to each resource block, it is first necessary to calculate the superimposed signal on the resource block according to all possible bit information, and the superimposed signal is the transmission signal of all users occupying the resource block, Then, the minimum Euclidean distance judgment is performed on the superimposed signal signal to obtain the target superimposed signal corresponding to the minimum Euclidean distance. It should be noted that each resource block has multiple possible bit information, so each resource block Correspondence will calculate multiple superimposed signals, and then lock the target superimposed signal that matches the resource block, and then find out the corresponding target bit information according to the target superimposed signal, so as to decode the target bit information corresponding to all resource blocks in parallel, Then the signals transmitted by each user are obtained, and then the entire decoding work is completed. The complexity of the entire decoding process is low, and the bit error rate is low at the same time.

综上，根据上述的SCMA辅助可见光通信的快速译码方法，通过特定码本结构，以对发射端的信号进行拆分，并根据码本可拆分特点，将发射端的信号和码字进行拆分重组，并对码字重组后的序列和叠加信号设置成唯一可译的特点，进而完成对接收信号的解码，具有复杂度低以及误码率性能良好的优点。具体为：发送端首先通过一全新的特定码本对多个用户的比特信号进行码本映射，进而使得比特信号实现信号叠加，得到复数信号，而后再对复数信号分别进行调制转换和信道增益，再将完成信号增益的正实数信号发送给接收端，接收端再将接收到的正实数信号进行对应的解调，而后将解调后得到的复数接收信号进行横向维度的拆分，以获取每一资源块可能存在的所有比特信息，进而根据所有的比特信息计算出可能存在的所有叠加信号，而后基于最小欧式距离准则对所有可能的叠加信号进行判决，以得到目标叠加信号，进而按照该目标叠加信号对每个资源块进行并行解码，从而解码出每个用户所发射的信号，整个解码过程较为简单，同时针对更大过载率和更高阶的VLC-SCMA系统检测具有良好的适用性。In summary, according to the above-mentioned fast decoding method for SCMA-assisted visible light communication, the signal at the transmitting end is split through a specific codebook structure, and the signal and codeword at the transmitting end are split according to the splittable characteristics of the codebook. Recombination, and set the recombined codeword sequence and superposition signal to be uniquely decodable, and then complete the decoding of the received signal, which has the advantages of low complexity and good bit error rate performance. Specifically, the sending end first performs codebook mapping on the bit signals of multiple users through a new specific codebook, so that the bit signals can be superimposed to obtain complex signals, and then perform modulation conversion and channel gain on the complex signals respectively. Then send the positive real number signal that has completed the signal gain to the receiving end, and the receiving end will demodulate the received positive real number signal correspondingly, and then split the complex number received signal obtained after demodulation in the horizontal dimension to obtain each All the bit information that may exist in a resource block, and then calculate all the possible superimposed signals based on all the bit information, and then judge all possible superimposed signals based on the minimum Euclidean distance criterion to obtain the target superimposed signal, and then according to the target The superimposed signal decodes each resource block in parallel to decode the signal transmitted by each user. The whole decoding process is relatively simple, and it has good applicability for detection of larger overload rate and higher order VLC-SCMA system.

请参阅图2，所示为本发明第二实施例中的SCMA辅助可见光通信的快速译码方法的流程图，该方法包括步骤S101至步骤S108，其中：Please refer to FIG. 2 , which is a flow chart of a fast decoding method for SCMA-assisted visible light communication in the second embodiment of the present invention. The method includes steps S101 to S108, wherein:

步骤S101：发送端获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号；Step S101: The transmitting end obtains bit signals of multiple users, and performs codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain a complex signal;

需要说明的是，在本实施例中，构建该特定码本的步骤具体如下：It should be noted that, in this embodiment, the steps of constructing the specific codebook are as follows:

根据实际应用场景的需求获取过载率目标值，并根据所述过载率目标值设定对应的码本大小、用户最大承载数量、资源块个数以及每个资源块过载用户数；Obtaining the target value of the overload rate according to the requirements of the actual application scenario, and setting the corresponding codebook size, the maximum number of bearers of users, the number of resource blocks, and the number of overloaded users for each resource block according to the target value of the overload rate;

将所述特定码本中的母星座结构定义为行矩阵，所述行矩阵中包括两种互为相反数的字符，并根据所述码本大小设定所述行矩阵中的字符数量，具体的，每种字符的数量均为所述码本大小的算术平方根；Defining the mother constellation structure in the specific codebook as a row matrix, the row matrix includes two characters with opposite numbers to each other, and setting the number of characters in the row matrix according to the size of the codebook, specifically , the number of each character is the arithmetic square root of the codebook size;

根据每个资源块过载用户数对所述母星座结构进行旋转操作和功率分配，以构建得到与每个资源块对应的因子矩阵，旋转操作次数与每一资源块承载的用户数相同。Perform rotation operation and power allocation on the mother constellation structure according to the number of overloaded users of each resource block to construct a factor matrix corresponding to each resource block, and the number of rotation operations is the same as the number of users carried by each resource block.

示例而非限定，以M=4，J=6，K=4，df=3为例，其母星座结构设计如下所示：As an example and not a limitation, take M=4, J=6, K=4, and df=3 as an example, and the parent constellation structure design is as follows:

其中的A即表示字符，而后再对该母星座做旋转操作和功率分配，其中旋转操作为母星座乘e^α，且α=jφ_iπ，其中，就表示因子矩阵的第j列，φ_i表示在占用资源块第i个用户的旋转角度，由于每个资源块占3个用户，需旋转三次，进一步需要为这3个用户分配功率，由于每个资源块的功率相同为MJ/K，其中，M表示码本大小，J表示所有资源块的最大用户承载数量，K表示资源块数量，以E_i表示为第i个用户分配的功率，则在一个资源块上，E_i的和为MJ/K，最后得到这3个用户的一维星座，进而将因子矩阵中的非零元素设定为C_i，C_i即表示用户i的一维星座，进而得到的因子矩阵F如下所示：The A in it represents the character, and then the rotation operation and power distribution are performed on the mother constellation, where the rotation operation is the mother constellation multiplied by e ^α , and α=jφ _i π, where it represents the jth column of the factor matrix, φ _i Indicates the rotation angle of the i-th user occupying the resource block. Since each resource block occupies 3 users, it needs to rotate three times. Further, it is necessary to allocate power for these 3 users. Since the power of each resource block is the same as MJ/K, Among them, M represents the size of the codebook, J represents the maximum number of users carried by all resource blocks, K represents the number of resource blocks, and E _i represents the power allocated to the i-th user, then on a resource block, the sum of E _i is MJ/K, finally get the one-dimensional constellation of these three users, and then set the non-zero elements in the factor matrix to C _i , C _i represents the one-dimensional constellation of user i, and then the obtained factor matrix F is as follows :

步骤S102：将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；Step S102: ACO-OFDM modulation is performed on the complex signal to convert it into a positive real signal, and the positive real signal is channel-gained and then transmitted to the receiving end;

所述接收端将接收到的信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号。The receiving end performs ACO-OFDM demodulation on the received signal, so as to convert the positive real signal into a complex received signal.

步骤S103：根据所述特定码本对所述复数接收信号进行逐位拆分，并将拆分后得到的比特信息进行码本映射，以将所述复数接收信号转换为单比特信息；Step S103: Splitting the complex received signal bit by bit according to the specific codebook, and performing codebook mapping on the bit information obtained after splitting, so as to convert the complex received signal into single-bit information;

首先对码本进行拆分，以4*6系统为例，如图3所示，为本实施例中的码本拆分映射解析图，通常情况下用户发送的2bit信号映射为一个K维向量，而根据特定码本可以将每个用户的两比特信息进一步逐位拆分，而其对应的K维向量也可进一步拆分，拆分后的信号以及映射码字，可以按位映射，即将多比特信息映射转换为单比特信息映射。First, the codebook is split. Taking the 4*6 system as an example, as shown in FIG. 3, it is the codebook splitting and mapping analysis diagram in this embodiment. Usually, the 2-bit signal sent by the user is mapped to a K-dimensional vector , and according to the specific codebook, the two-bit information of each user can be further split bit by bit, and the corresponding K-dimensional vector can also be further split, and the split signal and the mapped codeword can be mapped bit by bit, that is, Multi-bit information maps are converted to single-bit information maps.

步骤S104：根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号；Step S104: Obtain the user index occupying each resource block according to the factor matrix, so as to obtain all user numbers occupied on each resource block;

具体的，根据以下公式进行索引：Specifically, index according to the following formula:

其中，U(:，k)是表示在资源块k上占用的用户号，find表示find matlab函数，F表示因子矩阵。Among them, U(:, k) represents the user number occupied on the resource block k, find represents the find matlab function, and F represents the factor matrix.

步骤S105：根据每个资源块上占用的所有用户号以及得到的所有单比特信息列出占用每个资源块上的各个用户可能存在的所有比特序列的组合；Step S105: According to all user numbers occupied on each resource block and all obtained single-bit information, list all combinations of possible bit sequences of each user occupying each resource block;

示例而非限定，给出6个用户共用4个频谱资源块下的用户码本结构，以方便来解释具体操作，每个用户码本结构如下：As an example and not a limitation, the user codebook structure under 4 spectrum resource blocks shared by 6 users is given to explain the specific operation for convenience. The structure of each user codebook is as follows:

其中，CB₁、CB₂、CB₃、CB₄、CB₅以及CB₆分别表示6个用户的码本结构，A、B、C均表示字符。Wherein, CB ₁ , CB ₂ , CB ₃ , CB ₄ , CB ₅ , and CB ₆ represent codebook structures of six users respectively, and A, B, and C all represent characters.

假设6个用户发射信号如下：Suppose 6 users transmit signals as follows:

进一步地，将每个用户传输的两比特信息及其映射的码字进行拆分，即可以使单比特信息映射为占用一个资源块的四维码字，即将用户的两比特信息拆分在2个资源块上分开传输，对于资源块1，过载的用户为2，3，5，则用户2在资源块1上传输信号为0时其对应的码字为A，传输信号为1时其对应的码字为-A；Further, splitting the two-bit information transmitted by each user and its mapped codeword can make the single-bit information be mapped into a four-dimensional codeword occupying one resource block, that is, split the two-bit information of the user into two The resource blocks are transmitted separately. For resource block 1, the overloaded users are 2, 3, and 5. Then, when the transmission signal of user 2 on resource block 1 is 0, its corresponding codeword is A, and when the transmission signal is 1, its corresponding codeword is The code word is -A;

进一步地，将占用每个资源的df个用户传输二进制比特信号的所有可能组合列出；Further, list all possible combinations of df users transmitting binary bit signals occupying each resource;

例如：用户2，3，5，可能存在的比特序列有(0,0,0),(0,0,1),(0,1,0)……。For example: users 2, 3, 5, the possible bit sequences are (0,0,0), (0,0,1), (0,1,0)....

步骤S106：根据各个用户可能存在的所有比特序列的组合分别计算出与所述比特序列一一对应的叠加码字，每种所述比特序列与其对应的所述叠加码字具有唯一可译原则；Step S106: According to the combination of all possible bit sequences that may exist in each user, the superposition codeword corresponding to the bit sequence is calculated one by one, and each kind of bit sequence and the corresponding superposition codeword have a unique decipherable principle;

对于M=4,K=4,J=6时，每个用户在每个资源块上不同的码字仅有2个，因此可能存在的叠加码字有2³种，即可能存在的叠加码字数量为2^df种。For M=4, K=4, J=6, each user has only 2 different codewords on each resource block, so there are 2 ^{or 3} possible superimposed codewords, that is, the possible superimposed codewords The number of words is 2 ^df kinds.

示例而非限定，若对于其中的一组比特序列为(0,0,0)，则s(1)=A+B+C，其中，s(1)表示000对应的叠加码字，A表示用户2传输0时映射的码字，B表示用户3传输0时映射的码字，C表示用户5传输0时映射的码字，且所有的叠加码字s(j)唯一对应比特序列，例如：s(1)唯一对应比特序列(0,0,0)。As an example but not a limitation, if a set of bit sequences is (0,0,0), then s(1)=A+B+C, where s(1) represents the superposition codeword corresponding to 000, and A represents The code word mapped when user 2 transmits 0, B represents the code word mapped when user 3 transmits 0, C represents the code word mapped when user 5 transmits 0, and all superimposed code words s(j) uniquely correspond to bit sequences, for example : s(1) uniquely corresponds to the bit sequence (0,0,0).

通过用户特定码本，以增大每个用户发射信号中的码字之间的差异，即增加各个叠加信号的差异性，例如s(i)(0,0,0)=A+B+C≠s(j)(0,0,1)=A+B-C是非常明确的，也就是使得同一序列不会出现两个非常相近的叠加信号，进而为叠加码字赋予唯一可译特性提供可靠依据，同时经过噪声干扰的信号会因为失真而围绕在叠加信号周围，但不会相距太远，进而本方案采用最小欧式距离准则，选择根据距离相近对信号进行判决，即y_k-s(i)的距离最小时，可以判别出目标叠加信号，s(i)表示目标叠加码字。Through the user-specific codebook, the difference between the codewords in each user's transmitted signal is increased, that is, the difference of each superimposed signal is increased, for example, s(i)(0,0,0)=A+B+C ≠s(j)(0,0,1)=A+BC is very clear, that is, two very similar superimposed signals will not appear in the same sequence, and then provide a reliable basis for the superimposed codeword to be uniquely decodable , at the same time, the noise-interferenced signal will surround the superimposed signal due to distortion, but will not be too far apart, and then this scheme adopts the minimum Euclidean distance criterion, and chooses to judge the signal according to the similar distance, that is, y _k -s(i) When the distance of is the smallest, the target superimposed signal can be identified, and s(i) represents the target superimposed codeword.

通过构建特定码本，以增大每个用户发射信号的差异，具有多个用户传输比特信号可拆分特性，并将拆分信号与拆分码本进行映射，设定唯一可译准则，进一步的在接收端根据唯一可译准则，将接收的复数信号按资源块维度进行拆分，并通过每个资源块进行解码，具有将复杂度降低的效果。By constructing a specific codebook to increase the difference of each user's transmitted signal, it has the characteristics of splittable bit signals transmitted by multiple users, and maps the split signal with the split codebook, and sets a unique decipherable criterion, further At the receiving end, according to the unique translatability criterion, the received complex signal is split according to the resource block dimension, and each resource block is used for decoding, which has the effect of reducing the complexity.

步骤S107：所述根据每一资源块可能存在的叠加码字和所述复数接收信号计算出每种叠加码字分别与所述复数接收信号的欧式距离，并从获取的所有欧式距离中筛选出最小欧式距离，以根据所述最小欧式距离锁定与其对应的目标叠加码字；Step S107: Calculate the Euclidean distance between each superimposed codeword and the complex received signal according to the superimposed codewords that may exist in each resource block and the complex received signal, and select from all obtained Euclidean distances Minimum Euclidean distance, to lock the corresponding target superposition codeword according to the minimum Euclidean distance;

具体的，根据以下公式计算所述欧式距离：Specifically, the Euclidean distance is calculated according to the following formula:

其中，‖•‖表示求解欧式距离，min表示检索所有欧式距离中的最小值，y_k表示所述复数接收信号中的第k维信号，s(j)表示第j组比特序列所对应映射的叠加码字，m表示解码出的目标叠加码字所在的位置，用于检索目标叠加码字。Among them, ‖‖‖ means to solve the Euclidean distance, min means to retrieve the minimum value of all Euclidean distances, y _k means the k-th dimension signal in the complex received signal, s(j) means the corresponding mapping of the jth group of bit sequences The superimposed codeword, m represents the location of the decoded target superimposed codeword, and is used to retrieve the target superimposed codeword.

进一步地，根据以下公式获取所述复数接收信号中的第k维信号：Further, the k-th dimensional signal in the complex received signal is obtained according to the following formula:

y_k=Hx_k+ny _k =Hx _k +n

其中，x_k表示第k个资源块上df个用户的叠加信号，y_k表示复数接收信号的第k维信号，df表示第k个资源块上的用户数，H表示可见光信道增益，n表示高斯噪声。Among them, x _k represents the superimposed signal of df users on the k-th resource block, y _k represents the k-th dimension signal of the complex received signal, df represents the number of users on the k-th resource block, H represents the visible light channel gain, and n represents Gaussian noise.

步骤S108：基于所述唯一可译原则获取与所述目标叠加码字对应的目标比特序列，并根据在每一资源块上分别预设的解码器对各个资源块分别对应的目标比特序列进行并行解码。Step S108: Obtain the target bit sequence corresponding to the target superimposed codeword based on the unique translatability principle, and perform parallel processing on the target bit sequence corresponding to each resource block according to the decoder preset on each resource block decoding.

需要说明的是，每个资源块上均设有一个解码器，在实际解码过程中，通过对接收端的K维复数信号拆分为K维，并设计K个可并行解码的解码器，对接收信号进行解码，具有复杂度低以及误码率性能好的优点，进一步解决现有技术中解码复杂度过高的问题。It should be noted that each resource block is equipped with a decoder. In the actual decoding process, the K-dimensional complex signal at the receiving end is split into K-dimensional, and K decoders that can be decoded in parallel are designed. The signal is decoded, which has the advantages of low complexity and good bit error rate performance, and further solves the problem of excessive decoding complexity in the prior art.

请参阅下表1，所示为传统解码算法与本发明在各种运算中的复杂度，其中，dv表示因子矩阵的列重，K表示资源块数，M表示码本大小，N表示迭代次数，其中的MPA和LOG-MPA分别表示消息传递算法和基于对数域的MPA算法，由表1可以明显看出，MPA和LOG-MPA的各个运算次数远远大于本发明算法，同时随着过载因子的增加，其复杂度程指数增长，其复杂度对比结果为：MPA>LOG-MPA>本发明。Please refer to Table 1 below, which shows the complexity of the traditional decoding algorithm and the present invention in various operations, where dv represents the column weight of the factor matrix, K represents the number of resource blocks, M represents the size of the codebook, and N represents the number of iterations , where MPA and LOG-MPA respectively represent the message passing algorithm and the MPA algorithm based on the logarithmic domain. It can be clearly seen from Table 1 that the number of operations of MPA and LOG-MPA is far greater than that of the algorithm of the present invention. As the factor increases, its complexity increases exponentially, and its complexity comparison result is: MPA>LOG-MPA>the present invention.

表1Table 1

请参阅图4，所示为同一码本在150%情况下使用MPA检测和本实施检测算法的误码率性能对比图，其中“MPA“和“本发明”对应的是对同一码本的误码率性能曲线，Eb/N0表示的为比特信噪比，因此从图4可以明显看出，MPA检测和本实施检测算法的误码率性能相近，但本实施例检测过程的复杂度却远远小于MPA算法，从而使得本实施例提供的检测算法有利于针对更大过载率和更高阶的VLC-SCMA系统检测。Please refer to Figure 4, which shows the comparison of bit error rate performance using MPA detection and this implementation of the detection algorithm in the same codebook at 150%, where "MPA" and "the present invention" correspond to the error rate of the same codebook Bit rate performance curve, Eb/N0 represents the bit signal-to-noise ratio, so it can be clearly seen from Figure 4 that the bit error rate performance of MPA detection and the detection algorithm of this implementation is similar, but the complexity of the detection process of this embodiment is far away Much smaller than the MPA algorithm, so that the detection algorithm provided by this embodiment is beneficial to the detection of a larger overload rate and a higher order VLC-SCMA system.

综上，根据上述的SCMA辅助可见光通信的快速译码方法，通过特定码本结构，以对发射端的信号进行拆分，并根据码本可拆分特点，将发射端的信号和码字进行拆分重组，并对码字重组后的序列和叠加信号设置成唯一可译的特点，进而完成对接收信号的解码，具有复杂度低以及误码率性能良好的优点。具体为：发送端首先通过一全新的特定码本对多个用户的比特信号进行码本映射，进而使得比特信号实现信号叠加，得到复数信号，而后再对复数信号分别进行调制转换和信道增益，再将完成信号增益的正实数信号发送给接收端，接收端再将接收到的正实数信号进行对应的解调，而后将解调后得到的复数接收信号进行横向维度的拆分，以获取每一资源块可能存在的所有比特信息，进而根据所有的比特信息计算出可能存在的所有叠加信号，而后基于最小欧式距离准则对所有可能的叠加信号进行判决，以得到目标叠加信号，进而按照该目标叠加信号对每个资源块进行并行解码，从而解码出每个用户所发射的信号，整个解码过程较为简单，同时针对更大过载率和更高阶的VLC-SCMA系统检测具有良好的适用性。In summary, according to the above-mentioned fast decoding method for SCMA-assisted visible light communication, the signal at the transmitting end is split through a specific codebook structure, and the signal at the transmitting end and the codeword are split according to the splittable characteristics of the codebook. Recombination, and set the recombined codeword sequence and superposition signal to be uniquely decodable, and then complete the decoding of the received signal, which has the advantages of low complexity and good bit error rate performance. Specifically, the sending end first performs codebook mapping on the bit signals of multiple users through a new specific codebook, so that the bit signals can be superimposed to obtain complex signals, and then perform modulation conversion and channel gain on the complex signals respectively. Then, the positive real number signal that has completed the signal gain is sent to the receiving end, and the receiving end performs corresponding demodulation on the received positive real number signal, and then splits the complex received signal obtained after demodulation in the horizontal dimension to obtain each All the bit information that may exist in a resource block, and then calculate all the possible superimposed signals based on all the bit information, and then judge all possible superimposed signals based on the minimum Euclidean distance criterion to obtain the target superimposed signal, and then according to the target The superimposed signal decodes each resource block in parallel to decode the signal transmitted by each user. The whole decoding process is relatively simple, and it has good applicability for detection of larger overload rate and higher order VLC-SCMA system.

请参阅图5，所示为本发明第三实施例中的SCMA辅助可见光通信的快速译码系统的结构示意图，该系统包括：Please refer to FIG. 5 , which is a schematic structural diagram of a fast decoding system for SCMA-assisted visible light communication in a third embodiment of the present invention. The system includes:

所述发送端包括：The sender includes:

码本映射模块10，用于获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号；The codebook mapping module 10 is configured to obtain bit signals of multiple users, and perform codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain a complex signal;

信号调制模块20，用于将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；A signal modulation module 20, configured to perform ACO-OFDM modulation on the complex signal to convert it into a positive real number signal, and transmit the positive real number signal to the receiving end after performing channel gain;

所述接收端包括：The receiver includes:

信号解调模块30，用于将接收到的正实数信号进行解调，以将所述正实数信号转换为复数接收信号，并按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块可能存在的所有比特信息；The signal demodulation module 30 is configured to demodulate the received positive real number signal to convert the positive real number signal into a complex received signal, and split the complex received signal in a horizontal dimension according to the number of resource blocks , to obtain all bit information that may exist in each resource block according to the split result;

根据以下公式对所述正实数信号进行接收：The positive real number signal is received according to the following formula:

Y=HX+nY=HX+n

其中，Y表示接收信号，X表示正实数信号，H表示可见光信道增益，n表示高斯噪声；Among them, Y represents the received signal, X represents the positive real number signal, H represents the visible light channel gain, and n represents Gaussian noise;

所述接收端将接收到的信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号。The receiving end performs ACO-OFDM demodulation on the received signal, so as to convert the positive real signal into a complex received signal.

进一步地，所述信号解调模块30还包括：Further, the signal demodulation module 30 also includes:

信号拆分单元，用于根据所述特定码本对所述复数接收信号进行逐位拆分，并将拆分后得到的比特信息进行码本映射，以将所述复数接收信号转换为单比特信息；A signal splitting unit, configured to split the complex received signal bit by bit according to the specific codebook, and perform codebook mapping on the bit information obtained after splitting, so as to convert the complex received signal into a single bit information;

索引计算单元，用于根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号；An index calculation unit, configured to obtain the user index occupying each resource block according to the factor matrix, so as to obtain all user numbers occupied on each resource block;

根据以下公式进行索引：Indexed according to the following formula:

其中，U(:，k)是表示在资源块k上占用的用户号，find表示find matlab函数，F表示因子矩阵。Among them, U(:, k) represents the user number occupied on the resource block k, find represents the find matlab function, and F represents the factor matrix.

排列组合单元，用于根据每个资源块上占用的所有用户号以及得到的所有单比特信息列出占用每个资源块上的各个用户可能存在的所有比特序列的组合。The permutation and combination unit is configured to list all combinations of bit sequences that may exist for each user occupying each resource block according to all user numbers occupied on each resource block and all obtained single-bit information.

并行解码模块40，用于根据每一资源块上可能存在的所有比特信息计算出对应的所有可能的叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号。The parallel decoding module 40 is configured to calculate all possible superimposed signals corresponding to all possible bits of information on each resource block, and judge all the superimposed signals based on the minimum Euclidean distance criterion, so that according to the judgment result The target superposition signal corresponding to the minimum Euclidean distance is obtained, and each resource block is decoded in parallel according to the target superposition signal, so as to obtain the signal transmitted by each user.

进一步地，所述并行解码模块40还包括：Further, the parallel decoding module 40 also includes:

叠加码字计算单元，用于根据各个用户可能存在的所有比特序列的组合分别计算出与所述比特序列一一对应的叠加码字，每种所述比特序列与其对应的所述叠加码字具有唯一可译原则；The superposition codeword calculation unit is used to calculate the superposition codeword corresponding to the bit sequence one by one according to the combination of all the bit sequences that may exist in each user, each of the bit sequences and the superposition codeword corresponding to it have the principle of unique translatability;

欧式距离计算单元，用于根据每一资源块可能存在的叠加码字和所述复数接收信号计算出每种叠加码字分别与所述复数接收信号的欧式距离，并从获取的所有欧式距离中筛选出最小欧式距离，以根据所述最小欧式距离锁定与其对应的目标叠加码字；A Euclidean distance calculation unit, configured to calculate the Euclidean distance between each superimposed codeword and the complex received signal according to the superimposed codewords that may exist in each resource block and the complex received signal, and from all obtained Euclidean distances Screen out the minimum Euclidean distance to lock the corresponding target superimposed codeword according to the minimum Euclidean distance;

根据以下公式计算所述欧式距离：The Euclidean distance is calculated according to the following formula:

其中，‖•‖表示求解欧式距离，min表示检索所有欧式距离中的最小值，y_k表示所述复数接收信号中的第k维信号，s(j)表示第j组比特序列所对应映射的叠加码字，m表示解码出的目标叠加码字所在的位置，用于检索目标叠加码字。Among them, ‖‖‖ means to solve the Euclidean distance, min means to retrieve the minimum value of all Euclidean distances, y _k means the k-th dimension signal in the complex received signal, s(j) means the corresponding mapping of the jth group of bit sequences The superimposed codeword, m represents the location of the decoded target superimposed codeword, and is used to retrieve the target superimposed codeword.

解码执行单元，用于基于所述唯一可译原则获取与所述目标叠加码字对应的目标比特序列，并根据在每一资源块上分别预设的解码器对各个资源块分别对应的目标比特序列进行并行解码。A decoding execution unit, configured to obtain the target bit sequence corresponding to the target superimposed codeword based on the unique decodability principle, and assign target bits corresponding to each resource block according to a decoder preset on each resource block Sequences are decoded in parallel.

进一步地，在本发明一些可选的实施例中，该系统还包括：Further, in some optional embodiments of the present invention, the system also includes:

过载率获取模块，用于根据实际应用场景的需求获取过载率目标值，并根据所述过载率目标值设定对应的码本大小、用户最大承载数量、资源块个数以及每个资源块过载用户数；The overload rate acquisition module is used to obtain the target value of the overload rate according to the requirements of the actual application scenario, and set the corresponding codebook size, the maximum number of bearers of users, the number of resource blocks and the overload of each resource block according to the target value of the overload rate User number;

母星座构建模块，用于将所述特定码本中的母星座结构定义为行矩阵，所述行矩阵中包括两种互为相反数的字符，并根据所述码本大小设定所述行矩阵中的字符数量；The mother constellation building module is used to define the mother constellation structure in the specific codebook as a row matrix, the row matrix includes two characters with opposite numbers, and the row is set according to the size of the codebook the number of characters in the matrix;

因子矩阵构建模块，用于根据每个资源块过载用户数对所述母星座结构进行旋转操作和功率分配，以构建得到与每个资源块对应的因子矩阵。The factor matrix construction module is used to perform rotation operation and power allocation on the mother constellation structure according to the number of overloaded users of each resource block, so as to construct a factor matrix corresponding to each resource block.

进一步地，在本发明一些可选的实施例中，该系统还包括：Further, in some optional embodiments of the present invention, the system also includes:

接收信号处理模块，用于根据以下公式获取所述复数接收信号中的第k维信号：A received signal processing module, configured to obtain the kth dimensional signal in the complex received signal according to the following formula:

y_k=Hx_k+ny _k =Hx _k +n

其中，x_k表示第k个资源块上df个用户的叠加信号，y_k表示复数接收信号的第k维信号，df表示第k个资源块上的用户数，H表示可见光信道增益，n表示高斯噪声。Among them, x _k represents the superimposed signal of df users on the k-th resource block, y _k represents the k-th dimension signal of the complex received signal, df represents the number of users on the k-th resource block, H represents the visible light channel gain, and n represents Gaussian noise.

综上，根据上述的SCMA辅助可见光通信的快速译码方法，通过特定码本结构，以对发射端的信号进行拆分，并根据码本可拆分特点，将发射端的信号和码字进行拆分重组，并对码字重组后的序列和叠加信号设置成唯一可译的特点，进而完成对接收信号的解码，具有复杂度低以及误码率性能良好的优点。具体为：发送端首先通过一全新的特定码本对多个用户的比特信号进行码本映射，进而使得比特信号实现信号叠加，得到复数信号，而后再对复数信号分别进行调制转换和信道增益，再将完成信号增益的正实数信号发送给接收端，接收端再将接收到的正实数信号进行对应的解调，而后将解调后得到的复数接收信号进行横向维度的拆分，以获取每一资源块可能存在的所有比特信息，进而根据所有的比特信息计算出可能存在的所有叠加信号，而后基于最小欧式距离准则对所有可能的叠加信号进行判决，以得到目标叠加信号，进而按照该目标叠加信号对每个资源块进行并行解码，从而解码出每个用户所发射的信号，整个解码过程较为简单，同时针对更大过载率和更高阶的VLC-SCMA系统检测具有良好的适用性。In summary, according to the above-mentioned fast decoding method for SCMA-assisted visible light communication, the signal at the transmitting end is split through a specific codebook structure, and the signal and codeword at the transmitting end are split according to the splittable characteristics of the codebook. Recombination, and set the recombined codeword sequence and superposition signal to be uniquely decodable, and then complete the decoding of the received signal, which has the advantages of low complexity and good bit error rate performance. Specifically, the sending end first performs codebook mapping on the bit signals of multiple users through a new specific codebook, so that the bit signals can be superimposed to obtain complex signals, and then perform modulation conversion and channel gain on the complex signals respectively. Then send the positive real number signal that has completed the signal gain to the receiving end, and the receiving end will demodulate the received positive real number signal correspondingly, and then split the complex number received signal obtained after demodulation in the horizontal dimension to obtain each All the bit information that may exist in a resource block, and then calculate all the possible superimposed signals based on all the bit information, and then judge all possible superimposed signals based on the minimum Euclidean distance criterion to obtain the target superimposed signal, and then according to the target The superimposed signal decodes each resource block in parallel to decode the signal transmitted by each user. The whole decoding process is relatively simple, and it has good applicability for detection of larger overload rate and higher order VLC-SCMA system.

在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、 “示例”、“具体示例”、或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本发明的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不一定指的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任何的一个或多个实施例或示例中以合适的方式结合。In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

以上所述实施例仅表达了本发明的几种实施方式，其描述较为具体和详细，但并不能因此而理解为对本发明专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变形和改进，这些都属于本发明的保护范围。因此，本发明的保护范围应以所附权利要求为准。The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

1.一种SCMA辅助可见光通信的快速译码方法，其特征在于，所述方法包括：1. A fast decoding method for SCMA-assisted visible light communication, characterized in that the method comprises: 发送端获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号，其中，构建所述特定码本包括：The transmitting end obtains bit signals of multiple users, and performs codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain a complex signal, wherein the specific codebook is constructed include: 根据实际应用场景的需求获取过载率目标值，并根据所述过载率目标值设定对应的码本大小、用户最大承载数量、资源块个数以及每个资源块过载用户数；Obtaining the target value of the overload rate according to the requirements of the actual application scenario, and setting the corresponding codebook size, the maximum number of bearers of users, the number of resource blocks, and the number of overloaded users for each resource block according to the target value of the overload rate; 将所述特定码本中的母星座结构定义为行矩阵，所述行矩阵中包括两种互为相反数的字符，并根据所述码本大小设定所述行矩阵中的字符数量；Defining the female constellation structure in the specific codebook as a row matrix, the row matrix includes two characters with opposite numbers, and setting the number of characters in the row matrix according to the size of the codebook; 根据每个资源块过载用户数对所述母星座结构进行旋转操作和功率分配，以构建得到与每个资源块对应的因子矩阵；performing a rotation operation and power allocation on the mother constellation structure according to the number of overloaded users in each resource block, so as to construct a factor matrix corresponding to each resource block; 将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；ACO-OFDM modulation is performed on the complex number signal to convert it into a positive real number signal, and the positive real number signal is channel-gained and then transmitted to the receiving end; 所述接收端将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号，并按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块存在的所有比特信息，具体包括：The receiving end performs ACO-OFDM demodulation on the received positive real signal to convert the positive real signal into a complex received signal, and splits the complex received signal in a horizontal dimension according to the number of resource blocks, To obtain all the bit information of each resource block according to the split result, specifically including: 根据所述特定码本对所述复数接收信号进行逐位拆分，并将拆分后得到的比特信息进行码本映射，以将所述复数接收信号转换为单比特信息；Splitting the complex received signal bit by bit according to the specific codebook, and performing codebook mapping on the bit information obtained after splitting, so as to convert the complex received signal into single-bit information; 根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号；Obtain the user index occupying each resource block according to the factor matrix, so as to obtain all user numbers occupied on each resource block; 根据每个资源块上占用的所有用户号以及得到的所有单比特信息列出占用每个资源块上的各个用户存在的所有比特序列的组合；According to all user numbers occupied on each resource block and all single-bit information obtained, list all combinations of bit sequences that exist in each user occupying each resource block; 根据每一资源块上存在的所有比特信息计算出对应的所有叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号。Calculating all corresponding superimposed signals according to all bit information existing on each resource block, and judging all the superimposed signals based on the minimum Euclidean distance criterion, so as to obtain the target superimposed signal corresponding to the minimum Euclidean distance according to the judgment result, Each resource block is decoded in parallel according to the target superposition signal, so as to obtain the signal transmitted by each user. 2.根据权利要求1所述的SCMA辅助可见光通信的快速译码方法，其特征在于，所述接收端将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号的步骤包括：2. The fast decoding method for SCMA-assisted visible light communication according to claim 1, wherein the receiving end performs ACO-OFDM demodulation on the received positive real number signal to convert the positive real number signal into The steps for complex receiving signals include: 根据以下公式对所述正实数信号进行接收：The positive real number signal is received according to the following formula: Y=HX+nY=HX+n 其中，Y表示接收信号，X表示正实数信号，H表示可见光信道增益，n表示高斯噪声；Among them, Y represents the received signal, X represents the positive real number signal, H represents the visible light channel gain, and n represents Gaussian noise; 所述接收端将接收到的信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号。The receiving end performs ACO-OFDM demodulation on the received signal, so as to convert the positive real signal into a complex received signal. 3.根据权利要求2所述的SCMA辅助可见光通信的快速译码方法，其特征在于，所述根据每一资源块上存在的所有比特信息计算出对应的所有叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号的步骤包括：3. The SCMA-assisted fast decoding method for visible light communication according to claim 2, wherein all corresponding superimposed signals are calculated according to all bit information existing on each resource block, and based on the minimum Euclidean distance Judging all the superimposed signals according to the criterion, so as to obtain the target superimposed signal corresponding to the minimum Euclidean distance according to the judgment result, and performing parallel decoding on each resource block according to the target superimposed signal, so as to obtain the signal transmitted by each user. : 根据各个用户存在的所有比特序列的组合分别计算出与所述比特序列一一对应的叠加码字，每种所述比特序列与其对应的所述叠加码字具有唯一可译原则；According to the combination of all bit sequences existing in each user, superposition codewords corresponding to the bit sequences are calculated one by one, and each kind of bit sequence and the corresponding superposition codewords have a unique transcodable principle; 根据每一资源块存在的叠加码字和所述复数接收信号计算出每种叠加码字分别与所述复数接收信号的欧式距离，并从获取的所有欧式距离中筛选出最小欧式距离，以根据所述最小欧式距离锁定与其对应的目标叠加码字。Calculate the Euclidean distance between each superimposed codeword and the complex received signal according to the superimposed codeword existing in each resource block and the complex received signal, and select the minimum Euclidean distance from all obtained Euclidean distances, so as to The minimum Euclidean distance locks the corresponding target superposition codeword. 4.根据权利要求3所述的SCMA辅助可见光通信的快速译码方法，其特征在于，所述根据每一资源块上存在的所有比特信息计算出对应的所有叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号的步骤还包括：4. The SCMA-assisted fast decoding method for visible light communication according to claim 3, wherein all corresponding superimposed signals are calculated according to all bit information existing on each resource block, and based on the minimum Euclidean distance The criterion is to judge all the superimposed signals, so as to obtain the target superimposed signal corresponding to the minimum Euclidean distance according to the judgment result, and perform parallel decoding on each resource block according to the target superimposed signal, so as to obtain the signal transmitted by each user. include: 基于所述唯一可译原则获取与所述目标叠加码字对应的目标比特序列，并根据在每一资源块上分别预设的解码器对各个资源块分别对应的目标比特序列进行并行解码。The target bit sequence corresponding to the target superimposed codeword is obtained based on the unique transcodability principle, and the target bit sequence corresponding to each resource block is decoded in parallel according to a decoder preset on each resource block. 5.根据权利要求4所述的SCMA辅助可见光通信的快速译码方法，其特征在于，所述根据每一资源块存在的叠加码字和所述复数接收信号计算出每种叠加码字分别与所述复数接收信号的欧式距离，并从获取的所有欧式距离中筛选出最小欧式距离，以根据所述最小欧式距离锁定与其对应的目标叠加码字的步骤包括：5. The fast decoding method for SCMA-assisted visible light communication according to claim 4, characterized in that, according to the superimposed codewords existing in each resource block and the complex received signal, each superimposed codeword is calculated with The Euclidean distance of the complex received signal, and the minimum Euclidean distance is selected from all the obtained Euclidean distances, so that the step of locking the corresponding target superposition codeword according to the minimum Euclidean distance includes: 根据以下公式计算所述欧式距离：The Euclidean distance is calculated according to the following formula:

其中，‖•‖表示求解欧式距离，min表示检索所有欧式距离中的最小值，y_k表示所述复数接收信号中的第k维信号，s(j)表示第j组比特序列所对应映射的叠加码字，m表示解码出的目标叠加码字所在的位置，用于检索目标叠加码字。Among them, ‖‖‖ means to solve the Euclidean distance, min means to retrieve the minimum value of all Euclidean distances, y _k means the k-th dimension signal in the complex received signal, s(j) means the corresponding mapping of the jth group of bit sequences The superimposed codeword, m represents the location of the decoded target superimposed codeword, and is used to retrieve the target superimposed codeword. 6.根据权利要求5所述的SCMA辅助可见光通信的快速译码方法，其特征在于，所述根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号的步骤包括：6. The fast decoding method for SCMA-assisted visible light communication according to claim 5, wherein the user index occupying each resource block is obtained according to the factor matrix, so as to obtain all the user indexes occupied on each resource block The steps for user ID include: 根据以下公式进行索引：Indexed according to the following formula:

其中，U(:，k)是表示在资源块k上占用的用户号，find表示find matlab函数，F表示因子矩阵。Among them, U(:, k) represents the user number occupied on the resource block k, find represents the find matlab function, and F represents the factor matrix. 7.根据权利要求6所述的SCMA辅助可见光通信的快速译码方法，其特征在于，根据以下公式获取所述复数接收信号中的第k维信号：7. The fast decoding method for SCMA-assisted visible light communication according to claim 6, wherein the k-th dimensional signal in the complex received signal is obtained according to the following formula: y_k=Hx_k+ny _k =Hx _k +n 其中，x_k表示第k个资源块上df个用户的叠加信号，y_k表示复数接收信号的第k维信号，df表示第k个资源块上的用户数，H表示可见光信道增益，n表示高斯噪声。Among them, x _k represents the superimposed signal of df users on the k-th resource block, y _k represents the k-th dimension signal of the complex received signal, df represents the number of users on the k-th resource block, H represents the visible light channel gain, and n represents Gaussian noise. 8.一种SCMA辅助可见光通信的快速译码系统，其特征在于，所述系统包括发送端和接收端，其中：8. A fast decoding system for SCMA-assisted visible light communication, characterized in that the system includes a sending end and a receiving end, wherein: 所述发送端包括：The sender includes: 码本映射模块，用于获取多个用户的比特信号，并根据预先构建的特定码本对所述比特信号进行码本映射，以对所述比特信号进行信号叠加，得到复数信号，其中，构建所述特定码本包括：The codebook mapping module is used to obtain the bit signals of multiple users, and perform codebook mapping on the bit signals according to a pre-built specific codebook, so as to perform signal superposition on the bit signals to obtain complex signals, wherein, constructing The specific codebook includes: 过载率获取模块，用于根据实际应用场景的需求获取过载率目标值，并根据所述过载率目标值设定对应的码本大小、用户最大承载数量、资源块个数以及每个资源块过载用户数；The overload rate acquisition module is used to obtain the target value of the overload rate according to the requirements of the actual application scenario, and set the corresponding codebook size, the maximum number of bearers of users, the number of resource blocks and the overload of each resource block according to the target value of the overload rate User number; 母星座构建模块，用于将所述特定码本中的母星座结构定义为行矩阵，所述行矩阵中包括两种互为相反数的字符，并根据所述码本大小设定所述行矩阵中的字符数量；The mother constellation building module is used to define the mother constellation structure in the specific codebook as a row matrix, the row matrix includes two characters with opposite numbers, and the row is set according to the size of the codebook the number of characters in the matrix; 因子矩阵构建模块，用于根据每个资源块过载用户数对所述母星座结构进行旋转操作和功率分配，以构建得到与每个资源块对应的因子矩阵；A factor matrix construction module, configured to perform a rotation operation and power allocation on the mother constellation structure according to the number of overloaded users of each resource block, so as to construct a factor matrix corresponding to each resource block; 信号调制模块，用于将所述复数信号进行ACO-OFDM调制，以转换为正实数信号，并将所述正实数信号进行信道增益后传输到接收端；A signal modulation module, configured to perform ACO-OFDM modulation on the complex signal to convert it into a positive real number signal, and transmit the positive real number signal to the receiving end after performing channel gain; 所述接收端包括：The receiver includes: 信号解调模块，用于将接收到的正实数信号进行ACO-OFDM解调，以将所述正实数信号转换为复数接收信号，并按照资源块个数将所述复数接收信号进行横向维度的拆分，以根据拆分结果获取每一资源块存在的所有比特信息，具体包括：The signal demodulation module is used to perform ACO-OFDM demodulation on the received positive real number signal, so as to convert the positive real number signal into a complex received signal, and carry out the horizontal dimension of the complex received signal according to the number of resource blocks Split to obtain all bit information of each resource block according to the split result, specifically including: 信号拆分单元，用于根据所述特定码本对所述复数接收信号进行逐位拆分，并将拆分后得到的比特信息进行码本映射，以将所述复数接收信号转换为单比特信息；A signal splitting unit, configured to split the complex received signal bit by bit according to the specific codebook, and perform codebook mapping on the bit information obtained after splitting, so as to convert the complex received signal into a single bit information; 索引计算单元，用于根据所述因子矩阵获取占用每个资源块的用户索引，以得到每个资源块上占用的所有用户号；An index calculation unit, configured to obtain the user index occupying each resource block according to the factor matrix, so as to obtain all user numbers occupied on each resource block; 排列组合单元，用于根据每个资源块上占用的所有用户号以及得到的所有单比特信息列出占用每个资源块上的各个用户存在的所有比特序列的组合；The permutation and combination unit is used to list the combinations of all bit sequences that exist in each user occupying each resource block according to all user numbers occupied on each resource block and all obtained single-bit information; 并行解码模块，用于根据每一资源块上存在的所有比特信息计算出对应的所有叠加信号，并基于最小欧氏距离准则对所有的所述叠加信号进行判决，以根据判决结果获取最小欧式距离对应的目标叠加信号，并根据目标叠加信号对每个资源块进行并行解码，以得到每个用户发射的信号。A parallel decoding module, configured to calculate all corresponding superimposed signals according to all bit information existing on each resource block, and judge all said superimposed signals based on the minimum Euclidean distance criterion, so as to obtain the minimum Euclidean distance according to the judgment result corresponding target superposition signal, and perform parallel decoding on each resource block according to the target superposition signal, so as to obtain the signal transmitted by each user.