Guangdong University of Technology

Yi Fang

Guojun Han

Yiwei Tao

Liang Lv

Huan Ma

Chang Liu

Dingfei Ma

Bo Nie

Yun Xu

Hongmin Wei

Yu Zhou

Pingping Chen

Yuyi He

Liuguo Yin

Xiaomin Li

Jiacheng Xu

Yanhua Tan

Yurong Wang

Yujing Lu

Disclosed are a transceiver decoding method and system based on protograph differential chaos shift keying (DCSK), the method including acquiring an information bit sequence, performing a coded modulation on the information bit sequence via a protograph DCSK transmitter, and outputting a plurality of modulated symbols; inputting each modulated symbol into a wireless channel for channel interference, and outputting a received symbol corresponding to each modulated symbol; using a target extrinsic information-aided network to determine a target a-posteriori probability vector corresponding to each received symbol; inputting each target a-posteriori probability vector into an a-priori calculation decoder for decoding, and outputting an initial decoded bit sequence; and determining a target decoded bit sequence according to the initial decoded bit sequence and a preset check matrix. The technical problem of lower decoding accuracy caused by the existing transceiver decoding methods designed for a DCSK system is solved.

Transceiver decoding method and system based on protograph differential chaos shift keying

A signal transmission method based on constellation-aided LoRa modulation includes: a modulated bit sequence and a phase shift keying (PSK) bit sequence are obtained, and the modulated bit sequence is subjected to Gray mapping and spread spectrum modulation to generate a LoRa signal set; the PSK bit sequence is subjected to PSK constellation mapping based on a preset constellation point coordinate set to output a PSK constellation point set; the LoRa signal set is subjected to PSK modulation based on a preset imaginary unit and the PSK constellation point set to generate a transmission signal; a complex number sequence is generated based on the transmission signal and a preset raw down chirp signal; and real-imaginary part judgment is performed on the complex number sequence to output a LoRa modulation information sequence set and a PSK symbol judgment result. A signal transmission system based on CA-LoRa is further provided.

Signal transmission method and system based on constellation-aided LoRa

A coding method based on multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM) is provided. A coded bit sequence is divided into an index-layer sequence and a symbol-layer sequence. According to the index-layer sequence and the symbol-layer sequence, a plurality of constellation modes respectively corresponding to the plurality of subcarriers and which one of a plurality of constellation symbols respectively corresponding to the plurality of constellation modes is carried by each of the plurality of subcarriers are determined. A constellation mode permutation corresponding to each of the plurality of subcarriers is in a symmetrical distribution. The coded bit sequence is converted into the plurality of constellation symbols. The plurality of constellation symbols are respectively loaded to the plurality of subcarriers. A coding device based on MM-OFDM-IM is also provided.

Coding method and device based on multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM)

Disclosed is an identity authentication system for distributed Internet of vehicles (IoV), including a core cloud, a plurality of edge clouds, a plurality of road side units (RSUs) and a plurality of terminal vehicles. The core cloud stores registration information about the terminal vehicles and the RSUs; the edge cloud performs identity verification on the RSUs according to the registration information, and after the verification is passed, the edge cloud generates a temporary shared session key and sends the same to the RSU and the terminal vehicle, and the RSU and the terminal vehicle establish encrypted communication according to the temporary shared session key, to provide a network communication service for the terminal vehicle. In the present disclosure, a vehicle identity authentication efficiency in a scene with a large traffic density can be effectively improved.

Identity authentication system for distributed Internet of vehicles

A training method based on an improved protograph neural decoder includes the following steps: a to-be-trained decoding network is constructed based on an initial variable sub-network layer, an initial check sub-network layer and a preset shuffled belief-propagation (BP) sub-network layer; the initial variable sub-network layer, the initial check sub-network layer and the preset shuffled BP sub-network layer are updated and trained by calculating log-likelihood ratio (LLR) based on a preset mean square error loss function and a preset decoder objective function to obtain a target protograph neural decoder; and the preset mean square error loss function is configured to calculate a loss value between output information of the check sub-network layer and the preset shuffled BP sub-network layer. The target protograph neural decoder includes an optimized variable sub-network layer, an optimized check sub-network layer and an optimized shuffled BP sub-network layer. A training device is also provided.

Training method and device based on improved protograph neural decoder

A differential chaos shift keying (DCSK) communication method based on three-dimensional constellation is provided. Target information bit is mapped to a three-dimensional constellation symbol. An initial chaotic signal generated by a chaotic generator is processed by cyclic shift to generate a chaotic signal group including the initial chaotic signal, a first shifted chaotic signal and a second shifted chaotic signal. Information modulation is performed based on the three-dimensional constellation symbol and the chaotic signal group to obtain an information-bearing signal. A transmission signal is generated based on the information-bearing signal and the initial chaotic signal, and sent to a receiver to generate a received signal, which is subjected to information recovery analysis in the receiver to obtain an estimated information bit. A DCSK communication device based on three-dimensional constellation is also provided.

Differential chaos shift keying (DCSK) communication method and device based on three-dimensional constellation

A reconstruction method for DCSK signals is provided. An information bit sequence to be transmitted is acquired, which is processed by serial-to-parallel conversion. A processed information bit sequence is input into a modulator for modulation to obtain a modulated signal matrix. Cross multiplication is performed between the modulated signal matrix and a chaotic signal to obtain an original information-bearing matrix, which is reconstructed according to a predetermined reconstruction matrix to obtain an information-bearing reconstruction matrix. A transmission symbol is generated according to the information-bearing reconstruction matrix and a reference signal matrix in combination with frame structure information of the transmission symbol, and is sent to a receiving end via a wireless network to demodulate a received signal according to a reconstruction matrix. A reconstruction device for DCSK signals is also provided.

Reconstruction method and device for multi-carrier differential chaos shift keying (DCSK) signal

A non-coherent long range (LoRa) communication system based on multiple-input multiple-output (MIMO) technology, including a transmitter and a receiver. The transmitter is configured to transmit signals to the receiver, and the receiver is configured to receive and demodulate the signals. The transmitter includes a bit-symbol converter, a space-time mapper, and a plurality of transmitting antennas. The space-time mapper is configured to select a transmit antenna for the signal in each transmission time slot and transmit a base Chirp signal xand the modulating signal xto the receiver in different time slots. The receiver includes a plurality of receiving antennas. The receiving antenna is configured to preprocess the signal to obtain a first cache matrix and a second cache matrix. After Hadamard product operation is performed on the first and second cache matrixes, operation results of the receiving antennas are accumulated and demodulated to output demodulated information bits.

Non-coherent long-range (LoRa) communication system based on multiple-input multiple-output (MIMO) technology

A differential chaos shift keying communication method based on hybrid index, including: modulating a transmitted signal based on the hybrid index; and demodulating a received signal based on the hybrid index. The hybrid index is a hybrid index bit, which includes a carrier index bit and a carrier number index bit. This application also provides a system for implementing the differential chaos shift keying communication method, which includes a transmitter and a receiver.

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Guangzhou, China

Yi Fang