15 results about "Maximum likelihood detection" patented technology

The invention belongs to the technical field of wireless communication, and particularly relates to a communication sensing integrated system based on non-orthogonal AFDM (Alternating Frequency Division Multiplexing). According to the system, a bandwidth compression factor is introduced into an AFDM framework to construct a non-orthogonal waveform, and controllable overlapping between chirp subcarriers is realized, so that the spectrum utilization rate is improved, and the robustness of the system under a high-speed dynamic channel is enhanced. And a receiving end realizes reliable information recovery through maximum likelihood detection, and processes echo signals in combination with a two-dimensional parameter estimation algorithm so as to realize high-precision sensing of the target distance and speed. The system has good anti-Doppler capability and perception precision performance, and is suitable for communication perception fusion application in a high-speed mobile scene.

The invention discloses an OTFS cross-domain iteration detection method and system based on a penalty term sharing alternating direction multiplier method, mainly solving the problem of poor performance in a high-order modulation scene in the prior art, and the scheme comprises the following steps: a sending end sends a time domain signal; a receiving end receives the sent signal and constructs a penalty term sharing maximum likelihood detection problem and an augmented Lagrange function about the received signal; solving a penalty term sharing problem by utilizing an alternating direction multiplier method to obtain time domain posterior information, and calculating out-of-time domain information by utilizing the time domain posterior information; information outside a time domain is converted to a time delay-Doppler domain through cross-domain message transmission, and time delay-Doppler domain prior information is obtained; and time delay-Doppler out-of-domain information is calculated and fed back to the time domain module. And repeating the steps of the receiving end until the covariance of the symbol to be detected is smaller than a certain threshold value or reaches the set maximum iteration times, thereby obtaining a final judgment bit. According to the method, good detection performance can still be kept in a high-order modulation scene, and the method can be used for recovering a transmitting signal from an OTFS system receiving signal.

The application discloses an RIS-CSK index modulation method based on Hash mapping and belongs to the technical field of visible light communication and intelligent reflecting surface. The method realizes data transmission by constructing a communication system composed of an LED transmitting end, a Hash mapping module, an RIS reflecting array and a PD receiving array. The transmitting end divides input data bits into CSK modulation data and RIS index data, wherein the CSK data generates an RGB optical signal through M-order color shift keying modulation, and the index data generates an RIS activation mode through a Hash function mapping to control RIS group reflection. The receiving end uses a maximum likelihood detection algorithm to jointly detect CSK modulation symbols and RIS index information, and uses a maximum minimum Euclidean distance optimization strategy to improve the distinguishability between received signals. The application can realize efficient and stable data transmission in a visible light communication scene where a line-of-sight link is blocked, and reduce the system bit error rate.

Provided are a method and device for determining an interference layer modulation scheme, a program product, a communication device and a storage medium, applied to the technical field of communications, the method for determining an interference layer modulation scheme comprising: acquiring first frequency domain received signals on a plurality of first subcarriers, the first frequency domain receiving signal is obtained by converting a time domain receiving signal which is received by the receiver and corresponds to the target user; calculating a first metric value corresponding to each first frequency domain receiving signal; traversing a preset interference layer modulation scheme set for a first subcarrier where the first frequency domain receiving signal whose first metric value is not less than a preset threshold value is located, and calculating a second metric value corresponding to each interference layer modulation scheme based on a maximum likelihood detection criterion; and determining the interference layer modulation scheme with the minimum second metric value as a target modulation scheme corresponding to the interference signal.

A two-step detection method, system and device based on maximum likelihood criterion belong to wireless communication technology field, the method includes detecting and sorting all possible symbol constellation combinations through maximum likelihood detection algorithm, and selecting the symbol constellation combination with the minimum distance value as the preliminary decoding result based on the maximum likelihood criterion to complete the first step detection; setting a detection threshold, and finding all other distance values within the detection threshold range from the distance value corresponding to the preliminary decoding result based on the distance value sorting obtained in the first step detection, and storing the corresponding symbol constellation combination in the alternative set; using a different measurement standard from the first step maximum likelihood detection algorithm, and performing the second step detection on the symbol constellation combinations in the alternative set based on the maximum likelihood criterion to find the symbol constellation combination with the minimum measurement value as the target decoding signal. The application aims to solve the "error code platform" problem and effectively improve the accuracy and reliability of decoding.

The application discloses a kind of intelligent reflecting surface assisted spatial modulation system reflection coefficient optimization method, belong to wireless communication field, the information bits to be sent of sending end is divided into several information blocks with same length, according to each information block selects corresponding active antenna and sends specific signal;Optimize the coefficient of reflecting element on intelligent reflecting surface, maximize the Euclidean distance between different receiving signals;Maximum likelihood detection decoding is used at receiving end, and the original information bits are recovered.The application combines intelligent reflecting surface with spatial modulation scheme, reconstructs wireless channel using intelligent reflecting surface, increases the Euclidean distance between different receiving signals, improves the error performance of system, and can obtain better error performance than existing algorithm under the same condition.

The application discloses a method for analyzing bit error rate performance in a space modulation assisted affine frequency division multiplexing system; in the space modulation mode, information bits are mapped into constellation symbols and indexes of activated antennas, the system experiences a time-frequency double selective channel after affine frequency division multiplexing modulation, linear minimum mean square error equalization is performed on the affine Fourier transform domain received signal after affine frequency division multiplexing demodulation at the receiving end, then the equalized signal is grouped, maximum likelihood detection is performed on each carrier symbol to obtain estimated symbols and activated antenna indexes, and the estimated symbols and activated antenna indexes are demapped into bits; theoretical approximate closed expressions of error probabilities of transmitting symbol detection and activated antenna index detection are derived respectively, and the average bit error rate of the system is obtained; through simulation verification, the performance analysis method provided by the application can effectively measure the average bit error rate performance of the system.

The present application relates to the field of communication signal processing, and relates to a MIMO detection method, device and intelligent fusion terminal based on dynamic detection tree generation, wherein the MIMO detection method based on dynamic detection tree generation comprises: acquiring a multi-antenna receiving signal and channel state information; performing upper triangular decomposition on the channel state information to perform equivalent transformation on the receiving signal; converting a maximum likelihood detection solving process of MIMO detection into a dynamic generation process of a detection tree; initializing the detection tree, starting iteration from the first layer of the detection tree, and stopping iteration until an iteration termination condition is met to determine an optimal path of the detection tree and obtain a MIMO detection result. The present application can reduce the number of calculation nodes in a scenario with a large number of transmitting antennas and improve MIMO detection efficiency.

This invention discloses a noncoherent GFSK demodulation method based on the K-best algorithm. It performs demodulation calculations on GFSK modulated signals using a multi-symbol maximum likelihood detection method. If the number of branches in the current demodulation calculation stage is greater than K, the demodulation value of stage k is calculated. Based on the demodulation values ​​of stages k-2, k-1, and k, and the received symbol value of stage k-1, a conjugate relation value is calculated. K is the preset number of branches to retain in each stage, k is the current demodulation calculation stage, and the conjugate relation value is the relationship between the received symbol value and the demodulation value of stage k-1. The similarity value between the received symbol value and the demodulation value of stage k-1 is calculated based on the conjugate relation value and the corresponding branch integrator value. The K branch demodulation values ​​with the highest similarity values ​​are retained. The demodulation values ​​of the next K branches are calculated based on the retained K branch demodulation values ​​until stage T demodulation calculations are completed. The maximum value among the K branch demodulation values ​​of stage T is selected as the final demodulation value, where T is the observation length of the multi-symbol maximum likelihood detection method.

The invention discloses a spatial modulation method and system assisted by double intelligent reflecting surfaces, and particularly relates to the technical field of wireless communication, and the method comprises the steps: dividing a to-be-transmitted information bit into two parts of data blocks; the sending end modulates a constellation symbol according to the first data block, and assigns a receiving antenna index according to the second data block input bit information; the two intelligent reflecting surfaces adjust the phases of all reflecting units in the intelligent reflecting surfaces, so that the signal power on the target receiving antenna corresponding to the two intelligent reflecting surfaces is maximized; and the receiving end detects the receiving antenna index and the sent data symbol in a maximum likelihood detection mode according to the received signal, and recovers the information bit. According to the invention, communication is carried out through the double intelligent reflecting surfaces, so that the error rate of the system is reduced, the signal receiving quality is improved, and the system performance is improved.

The present disclosure discloses systems and methods of calculating a near-maximum likelihood detection (MLD) performance capability signal to interference plus noise ratio (SINR) according to instructions stored in non-transitory computer readable memory that when executed by a processor of a multiple-input, multiple output orthogonal frequency-division multiplexing (MIMO-OFDM) wireless communications receiver device cause the processor to perform operations including the processor acquiring Hi and noise variance σn2 for each subcarrier of a set of subcarriers between a MIMO-OFDM wireless communications transmitter device and the wireless communications receiver device, computing an average received bit mutual information rate (RBIR) over all subcarriers, converting the average RBIR to an effective SINR; and selecting a modulation coding scheme (MCS).

The invention relates to the field of communication signal processing, in particular to an MIMO detection method and device based on dynamic detection tree generation and an intelligent fusion terminal. The MIMO detection method based on dynamic detection tree generation comprises the following steps: acquiring a multi-antenna receiving signal and channel state information; performing upper triangular decomposition on the channel state information, and performing equivalent transformation on a received signal; and converting a maximum likelihood detection solving process of MIMO detection into a dynamic generation process of a detection tree: initializing the detection tree, and starting iteration from a first layer of the detection tree until an iteration termination condition is met so as to determine an optimal path of the detection tree and obtain an MIMO detection result. According to the invention, the number of calculated nodes can be reduced in a scene with a large number of transmitting antennas, and the MIMO detection efficiency is improved.

The invention discloses an MIMO (Multiple Input Multiple Output) detection maximum likelihood estimation method, which comprises the following steps of: acquiring a complex-valued transmitting signal and a complex-valued channel matrix between a receiving antenna and a transmitting antenna to obtain a complex-valued signal at a receiving end of a base station; according to the complex value transmitting signal, the complex value signal of the base station receiving end and the complex value channel matrix between the receiving antenna and the transmitting antenna, an optimal estimation signal is obtained, and MIMO maximum likelihood detection is mapped to an Isin model; mIMO maximum likelihood estimation is carried out through an Isin-MIMO detector, and a user emission signal is restored. The invention also discloses an Isin-MIMO (Multiple Input Multiple Output) detector. According to the method, the technical problem of how to accurately carry out MIMO detection maximum likelihood estimation in real time and output a result is solved.