73 results about "Gaussian channels" patented technology

In the method according to the present invention, a transmit power for each eigenbeam in a set of eigenbeams forming at least a portion of a multiple transmit antenna system is determined based on noise associated with each eigenbeam in the set of eigenbeams. The set of eigenbeams is for transmitting a number of parallel complex Gaussian channels.

A modulation identification method under an MIMO related channel based on a machine learning algorithm of the invention belongs to the field of communication. The method comprises the specific steps as follows: first, space-time coding is performed on each data flow of a communication transmitter, and code words are emitted out through Nt transmitting antennas; then, a correlation matrix (as shown in the description) of a receiver and a correlation matrix (as shown in the description) of the transmitter are received, and an MIMO channel matrix H is calculated; the received signal on each receiving antenna is calculated according to the MIMO channel matrix H and corrected; and finally, each receiving antenna extracts the features of the corresponding corrected signal, training test is performed on the extracted feature values, and a modulation identification mode to which a sample belongs is calculated. The advantages are as follows: the method has strong robustness and generalization ability to non-Gaussian channels, and modulation system identification under a more complex environment can be realized through parameter iteration; and by extracting high-order moment and high-order cumulant features, the signal feature difference is obvious under high signal-to-noise ratio, and the classification of a machine learning algorithm is facilitated.

The invention discloses a Polar code efficient adaptive decoding method based on Gaussian structure. Gaussian judgment is introduced based on the Gaussian structure to carry on path splitting and an effective adaptive decoding algorithm is combined. The method calculates the posteriori probability of each information bit by using the Gaussian structure under a Gaussian channel, and uses the posteriori probability as the decoding reliability of each information bit, and applies the decoding reliability of each information bit to a successive cancellation list (SCL) decoding. If the decoding (decoded as 0 or 1) reliability of a current bit is greater than the reliability of correct decoding, decoding is directly performed or if it is not satisfied, the path splitting is maintained. Decoding is performed by obtaining all effective paths of the current bit after the path splitting based on bit reliability in combination with the effective adaptive decoding algorithm. Numerical simulations show that under the same conditions, the method has lower complexity in the case of maintaining the same performance.

The invention discloses a constellation mapping de-mapping and the linear transformation planisphere mapping de-mapping method and the device, wherein the planisphere mapping method includes: performing the planisphere mapping to the coded and interweaved stream of bits according to planisphere satisfying G(alpha*d+ beta*D) smaller than the given threshold, mapping the code word onto the corresponding constellation point, transmitting the output signal flow after the post-treatment, wherein G is the cost function, d is the statistical value of the smallest euclidean distance of the input code word set, D is the statistical value of the smallest Hamming distance of the input code word set, alpha and beta are the weight coefficients which are selected according to the characteristics of the practical channel. The invention causes the modulation demodulation system to obtain the compromise between the receptivity of the gaussian channel and the fading channel, namely causes the modulation demodulation system to have the satisfying receptivity below the gaussian channel and the fading channel and other channels therebetween.

The invention discloses a multi-stage bit interleaved coded modulation method based on a polarization code, which mainly aims at a communication system under a complex Gaussian channel and comprises two parts of contents: polarization code coding and design of a bit-to-symbol mapping rule. In polar code coding, firstly, by designing sub-modulation orders of all levels, a traditional binary kernelcan be used for polar code coding of all levels, punching and construction of a multi-core polar code are avoided, and the polarization performance of the polar code is guaranteed. And then, calculating the reliability of the bit polarization channel through external information transfer, and selecting the high-reliability bit polarization channel to transmit information bits, thereby finishing polarization code coding. The design of a bit-to-symbol mapping rule mainly aims at mapping of a symmetric constellation diagram, and is hybrid mapping of joint set decomposition and Gray mapping. According to the invention, by designing the mapping rule from bits to symbols, the polarization performance can be improved to the maximum extent, so that the group error rate performance of the system isimproved.

The invention provides an OFDM channel estimation method and device. The method comprises: using an actual channel coefficient generated by simulation, an initial channel estimation of a pilot sequence that can be observed by a receiver after a fading channel and a Gaussian channel, forming a training set, and using a backward error propagation algorithm to off-line neural network training under different noise variances to determine neural network coefficients corresponding to different noise variances; using neural networks that are completely consistent with the offline neural network training, selecting neural network coefficients corresponding to current actual noise variances, and evulating online channels on OFDM symbols .According to the invention, the performance of channel estimation and the overall performance of channel estimation and equalization can be improved.

A method and apparatus for generating soft-decision information based on non-Gaussian channel in a wireless communication system is provided. A receiver receives a decision variable, models an interference or noise distribution in the decision variable as a non-Gaussian probability density function and estimates a number of parameters of the non-Gaussian probability density function, and determines a log likelihood ratio (LLR) of the decision variable using the results of the estimation, wherein the parameters of the non-Gaussian probability density function comprise a shape parameter for determining the shape of the non-Gaussian probability density function.

The invention relates to an energy efficiency maximum resource allocation method based on an unmanned aerial vehicle D2D communication network, and belongs to the technical field of communication. Themethod comprises the following steps: constructing a D2D communication network based on energy collection under the assistance of an unmanned aerial vehicle, the D2D communication network comprisingthe unmanned aerial vehicle, a ground terminal and a D2D user; enabling the unmanned aerial vehicle to hovering over the coverage area and serving as an air base station to send signals to the groundterminal, and enabling a D2D transmitter to collect radio frequency energy from the signals sent by the unmanned aerial vehicle and communicate with a receiver through the collected energy. And according to the flight height constraint of the unmanned aerial vehicle, the minimum energy collection constraint of the D2D user and the service quality constraint of the ground terminal, the position uncertainty and Gaussian channel uncertainty of the D2D user are considered, and a robust energy efficiency maximum resource allocation optimization problem is established. Experimental results show thatthe method can effectively improve the energy efficiency and robustness of the system.

The invention discloses a convex optimization technology-based method for enhancing the antijamming capability of a multi-carrier communication system of a cosine modulated filter bank, and belongs to the technical field of wireless communication. The method includes the following steps of: performing base band modulation and R bit string on an original signal at the transmitting end, and transforming to obtain a parallel signal; inserting a zero value into the parallel signal randomly; performing the modulation of the comprehensive cosine modulated filter bank on the signal into which the zero value is inserted, and transmitting the signal through a Gaussian channel; processing the received signal passing through the Gaussian channel by the receiving end, namely performing fast Fourier transform, performing frequency domain equilibrium on the signal, and performing fast Fourier transform on the signal to obtain a time domain signal; making the time domain signal pass through a convex optimization technology-based interference estimation module to obtain a jamming signal contained in the time domain signal, and performing subtraction operation on the time domain signal and the jamming signal to obtain a new signal; and performing operation of demodulation, base band demodulation and the like of a cosine modulated analysis filter bank on the new signal to obtain the originally-transmitted signal. By the convex optimization technology-based method, the reliability of signal transmission can be improved effectively.

The invention discloses a hybrid decoding method suitable for low-density parity check codes; the check nodes are classified according to the check node degrees by setting corresponding threshold values; the nodes with the degrees smaller than the threshold values are updated by adopting an APPROXIMATE-MIN* method based on linear interpolation; the nodes with the degrees larger than the thresholdvalues are calculated and updated by adopting a normalized correction minimum sum decoding method; the hybrid decoding method is suitable for a code rate compatible structure; the complexity and the decoding performance can be achieved in a better balanced way; thus, the complexity is reduced, and meanwhile, the decoding performance loss is reduced. Meanwhile, in the hybrid decoding method, a fixed factor multiplicative correction is used for decoding the input information, the dependence of the decoding method on the gaussian channel variance estimation is eliminated, and the complexity and the decoding performance are achieved in a better balanced way. According to the hybrid decoding method in the invention, the performance difference between the BP decoding method and the MS decoding method is reduced, and the dependence of the decoding method on the gaussian channel variance estimation is eliminated.

The invention discloses an energy detection method based on p-power wireless cooperative spectrum sensing. The energy detection method includes the following steps that under the Gaussian channel environment, p-power is used for replacing 2-power to obtain energy of each path of wireless electric signals, and a detection signal is substituted into a likelihood function to obtain detection statistics; a judgment threshold based on p-power detection is worked out by means of the Neyman-Pearson criterion according to given false alarm probability; the obtained statistics and the judgment threshold based on p-power detection are compared. According to the energy detection method, p-power is used for replacing changeless 2-power and is applied to cooperative spectrum detection; meanwhile, the mean and variance of decision variable p-power are approximated as the mean and variance of Gamma distribution, energy detection based on p-power wireless cooperative spectrum sensing is achieved, complexity is low, timeliness is high, p values can be selected according to different channel environments and signal intensity, and therefore detection performance is effectively improved.

The invention provides an underwater acoustic communication method using a polarization code and an equalizer. An underwater acoustic channel is converted into a Gaussian channel through the equalizer to construct the polarization code, and an HARQ mechanism is added to improve the performance of the scheme. According to the scheme, the bit error rate performance is superior to the result of turbo equalization iteration for five times, the decoding complexity is low, the coding structure is simple, and only noise variance information needs to be fed back when a polarization code receiving end is constructed by using a Gaussian approximation method.

The invention provides a signal to noise ratio estimator, system and method that are based on the constellation measurement. The signal to noise ratio estimator includes a constellation demodulator, a constellation measuring device and a signal to noise ratio estimator; wherein, the constellation demodulator demodulates the signal yn that is compensated by a channel compensator, and obtains the estimated value sn of the sending signal to be output to the constellation measuring device; the constellation measuring device carries out constellation measurement on the input signal yn and sn, works out the European distance |yn-sn| between yn and sn to be output to the signal to noise ratio estimator; the signal to noise ratio estimator judges if the channel is a Gaussian channel or flat fading channel according to the input channel information, and the signal to noise ratio of the Gaussian channel or flat fading channel can be estimated directly according to the |yn-sn|; if the channel is found to be a rapid fading channel, the signal to noise ratio of the rapid fading channel can be estimated according to the estimated channel response Hn and the input |yn-sn|. The invention also proposes the corresponding system and method, which decreases the complexity and has good estimation performance.

The invention discloses a system polarization code puncturing method and system based on reliability. The method comprises the steps of performing reliability calculation on a system polarization codewith a code length of N; assuming that an L bit needs to be shortened, firstly selecting the last L sub-channel as a first part of a frozen bit, taking the K sub-channel with the highest reliabilitymetric value as an information bit from the remaining (N to L) sub-channels, and taking the remaining sub-channels as a second part of the frozen bit; performing bit inversion replacement on the indexvalue of the first part of the frozen bit to obtain a codeword end punching vector index s; encoding the system polarization code; deleting codeword bits at corresponding positions according to the punching vector index s; transmitting the punctured system polarization code through a Gaussian channel; initializing a log-likelihood ratio corresponding to the punching index vector s to be infiniteat a decoding end; and evaluating the puncturing method. According to the invention, the system polarization code can adapt to different code lengths on the premise of not changing the basic structureof the system polarization code.

The present invention discloses an adaptive gray-level image pseudo-color processing method. The method comprises: performing statistics of the gray value of a gray-level image, and obtaining the appearance probability distribution of each gray value in the image; expanding the image in the dynamic range of the gray value from 0 to 255, and obtaining the gray value balance histogram of the image; selecting three most obvious peak values in the gray value balance histogram, and respectively taking the three peak values as the mean values of the three-color (red, green and blue) Gaussian channels; determining the variance of the Gaussian channels according to the distribution of the three peaks, distributing the weights for the Gaussian channels according to the difference of the probabilities of the three peaks, and obtaining the function expressions of the red, green and blue three-color Gaussian channels; and finally, passing the gray-level values through the red, green and blue three-color Gaussian channels, merging the output images, and obtaining a processed pseudo-color image. Through adoption of the image gray having approximate Gaussian distribution or a plurality of Gaussian distribution superposition characteristics, the adaptive gray-level image pseudo-color processing method solves the problem that the visual sense effect is not continuous by employing the pseudo-color processing technology in the prior art.

The invention discloses a Gaussian channel simulation method and a Gaussian channel simulation system. The Gaussian channel simulation method comprises the steps of (1) generating a communication signal s(t); (2) generating a Gaussian channel; and (3) simulating the Gaussian channel, to be specific, enabling the communication signal s(t) to pass through the Gaussian channel to obtain an output signal, analyzing the output signal and verifying the accuracy of the Gaussian channel. The invention also comprises a Gaussian channel simulation system. According to the Gaussian channel simulation method and the Gaussian channel simulation system, gain change caused by swinging of an antenna in mobile communication can be described.

The invention discloses a signal detection method for space time block code (STBC)-orthogonal frequency division multiplexing (OFDM) system under a condition of lack of a cyclic prefix, and belongs to the technical field of wireless communication. By eliminating inter-sign interference and reconstructing cyclic convolution, an OFDM transmission system is equivalent to N parallel Gaussian channels with different gains; and due to the orthogonality of an inter-antenna channel matrix, an STBC-OFDM sign can be detected. For the STBC-OFDM system for twice transmitting and once receiving, data received at a first time slot are subjected to inter-sign interference elimination firstly, the first approximation is performed on two time slot cyclic convolutions, and the data of the STBC-OFDM system are detected by virtue of the orthogonality of a space channel matrix and the diagonal capacity of a frequency domain channel matrix; and finally, the cyclic prefix of the data of two time slots are restored through iteration, and the data received by a second time slot are subjected to the inter-sign interference elimination, so that the data detection precision is improved.

The invention relates to an information communication method based on a puncture polarization code. Compared with the prior art, the information communication method has the advantages of solving thedefect that the puncture polarization code can only be applied to a Gaussian channel. The method comprises the following steps: obtaining data information; constructing the puncture polarization code;transmitting the data information; and receiving the data information. According to the information communication method, puncture construction can be performed on any non-memory binary symmetrical channel, and a better information bit set I can be obtained by the construction method to obtain a lower bit error rate and higher transmission efficiency.

The invention discloses a data detection method based on a simulated annealing neural network and interference elimination. The method comprises the following steps: acquiring spread spectrum data; modulating the spread spectrum data; judging whether 10 end users have been selected; generating mixed data; demodulating the mixed data; generating training sample data; constructing the simulated annealing neural network; training the simulated annealing neural network; judging whether the number of training iterations is less than 1000; acquiring simulated annealing neural network optimization data; acquiring interference elimination data; setting an initial value; calculating the total number of wrong elements; judging whether the current number of iterations is equal to the total number ofinterference elimination data elements; and detecting a data bit error rate. The data detection method based on the simulated annealing neural network and the interference elimination provided by theinvention can be used for detecting data sent by a user from the mixed data on a same frequency band in a Gaussian channel; and compared with the prior art, the detected data sent by the user have thelowest bit error rate.

The invention discloses a signal demodulation method based on an end-to-end cascade generative adversarial network. The method comprises the following steps: 1, carrying out dimension transformation on modulation information and demodulation information through data preprocessing to serve as a data set of a generative adversarial network; 2, mapping from modulation information to demodulation information is realized based on a demodulation model of the GAN network, so that signal demodulation is realized; 3, compensating the received information based on a channel estimation compensation model of the CGAN network, and then mapping to obtain stable modulation information; and 4, cascading the channel estimation compensation model based on the CGAN network and the demodulation model of the GAN network to form an end-to-end cascading generative adversarial network demodulation model. According to the method, the demodulation capability of the whole system is improved by utilizing the advantage that the target function of the GAN network is more constraint. In addition, a good coping strategy is still provided for a Gaussian channel and a Rayleigh fading channel.

The invention provides a non-orthogonal multiple access system codebook design method based on a resource block constellation distance. The non-orthogonal multiple access system codebook design method comprises the following steps: firstly, determining parameters J, M, N and K in an SCMA codebook according to user requirements; determining a mapping matrix of associated users and resource blocks in the codebook according to a Latin criterion; constructing an energy normalized N-dimensional constellation S0; calculating to obtain an optimal element coefficient and an optimal rotation angle through a particle swarm optimization (PSO) algorithm according to a criterion of maximizing the sum of codeword distances between constellation points of a resource block; finally, determining an optimal user constellation function according to the optimal element coefficient and the optimal rotation angle, and performing codeword rearrangement on a user constellation set corresponding to the optimal user constellation function; and distributing the code words before and after rearrangement to the mapping matrix, so that the SCMA multi-user codebook is obtained. According to the invention, a larger integer gain can be obtained, and the anti-noise performance of the SCMA system under a Gaussian channel is improved.

The invention relates to a wavelength division multiple access ultra-wideband multiuser detection method based on Gaussian mixture model clustering, relates to a wavelength division multiple access ultra-wideband multiuser detection method and aims to solve problem of poor real-time performance and low detection performance of a WDM ultra-wideband multi-user detection method in the prior art. Themethod comprises steps that S1, a WDM ultra-wideband signal under a Gaussian channel is obtained, the ultra-wideband signal is inputted into K matched filters for preliminary detection to obtain the matched filtering result y; S2, the matched filtering result y of K users is subjected to symbol decision and code element mapping, the matched filtering result y is mapped to be the code element mapping result conforming to a Gaussian mixture model; and S3, the code element mapping result phi(b<^>j) is subjected to Gaussian mixture model clustering, after an error code element is corrected, the WDM ultra-wideband multi-user detection result is outputted. The method is applied to the ultra-wideband communication field.

The invention discloses a method for improving the security of a physical layer of a collaborative network by using energy collection. The method comprises the following steps: combining energy collection with compressed sensing, wherein each relay node is provided with an energy collection receiver for converting a radio frequency signal into energy and amplifying a forwarding signal; performinginformation reception and energy conversion at the same time, adopting a power allocation relay criterion, dividing the received signal into two parts according to a power allocation ratio by the relay node for energy collection and information transmission; applying the converted energy to amplifying and forwarding the received information; analyzing the influence of different parameters to the security of the system in a Gaussian chassis, obtaining different optimal power allocation ratios in different channel environments so as to guarantee the security performance of the collaborative network. According to the method, the compressed sensing is combined with the energy collection technology for solving the problem that the energy is difficult to be provided for the relay node, and the radio frequency signal sent by the source node is converted into the energy of the relay, thereby ensuring the efficient use of the energy and the effective and secure transmission of the data.

The invention provides a method for capturing pseudocode under a non-Gaussian channel, which comprises the following steps: after being processed by the operations of carrier wave striping and pseudocode dispreading treatment, a received signal is converted into two observed quantities Xi and Xiof two I / Q branches; after being processed by the operation of squaring, the two observed quantities are added to the quadratic term gammaof a dispersion coefficient, and the obtained result is respectively divided by the two observed quantities of the I / Q branches to obtain reciprocal values so that the value of statistical quantity of each branch at a single time can be obtained; the values from 1 to M time (the variable of i) are sequentially processed by the steps of accumulation addition and square; and finally, the values of the two branches are added to each other to obtain and compare the statistical quantity with the threshold so as to judge whether a signal is captured or not, and the phase position of the local pseudocode is slid to carry out the operations of secondary judgment and comparison until the signal is captured under the circumstance that the statistical quantity is lower than the threshold. Proved by the result of comparison of performance simulation of the pseudocode capturing method of the invention and the traditional pseudocode capturing method, the detection performance of the pseudocode capturing method of the invention is drastically improved under the non-Gaussian noise environment, and the more obvious the pulse characteristic is, the more obvious the advantage of the detector designed by the invention can be.

A receiver (or transceiver) is selectable between a Gaussian mode and a non-Gaussian mode. In the non-Gaussian mode, a transformation block applies a non-linear transformation to signal samples to convert non-Gaussian noise in the signal samples to Gaussian or approximately Gaussian noise. In the Gaussian mode, the transformation block is bypassed. Samples are equalized using an equalizer configured to operate with a Gaussian or approximately Gaussian channel.

The invention provides a multiple access method based on physical layer network coding, the capacity limit can be achieved through a low-complexity coding and decoding algorithm, the energy spectrum efficiency can be remarkably improved, and the transmission rate can be flexibly adjusted and allocated according to user requirements. A multiple access channel capacity limit can be approached at low cost in both a Gaussian channel and a fading channel. The multiple access method provided by the invention comprises and is compatible with the schemes of IDMA, SCMA, PDMA, NOMA-SIC and the like. The LPNC-MA realizes channel coding, spreading code, sparse coding, modulation and the like of a plurality of users by using one code, so that the LPNC-MA can also be called as a Unified-Coded MA (UCMA) scheme, the performance of approaching channel capacity limit is achieved, and the transmission rate can be flexibly allocated to the users while high spectrum efficiency is kept.

An nth root transformation is used for generating near Gaussian metrics from non-Gaussian metrics for input into a conventional turbo decoder that is based on the assumption that the input sequence to the decoder has a Gaussian distribution. The nth root transformation transforms channel non-Gaussian statistics to near Gaussian statistics for use with conventional turbo decoding for improved noncoherent communications over a non-Gaussian channel, such as a fading channel. For a differential coherent PSK waveform, where the channel statistics of a demodulator are non-Gaussian, for example, in the presence of fading, the nth root transformation is used to transform the non-Gaussian statistics to near Gaussian statistics for generating near Gaussian metrics, for improved PSK communications.

The invention relates to the field of 5G communication, in particular to a bit flipping serial elimination list decoding method and system based on Gaussian optimization. The method comprises the following steps: performing CRC (cyclic redundancy check) on L screened paths, and continuing to execute a decoding process after bit flipping is performed on the L paths which do not pass the CRC; selecting a channel set higher than a reliability measurement preset threshold of the Gaussian channel, and taking an intersection with the first key flipping index set to obtain a second key flipping indexset; if the bit index in the decoding process belongs to a second key flipping index set, executing the decoding process after bit flipping to obtain L paths after bit flipping; performing CRC (cyclic redundancy check) on the L paths after bit flipping, if the L paths do not pass the CRC, changing a bit flipping index, and returning to the decoding process to continue iteration. According to themethod, the index set is optimized by adopting a Gaussian optimization method, so that the number of invalid indexes is reduced, and the purpose of reducing the decoding complexity is achieved.

The invention relates to a multi-carrier signal modulation method, and belongs to the technical field of wireless communication. The method comprises the following steps: grouping input bit information data; converting the grouped binary signals into complex signals by a CPM mapper; generating a subcarrier signal of each order of the PSWF and performing PSWF multi-carrier modulation; transmitting a transmitting signal to a receiving end through a Gaussian channel; the receiving end performing PSWF orthogonal subcarrier group matching on the received signals; and performing CPM de-mapping on the signal obtained in the previous step, combining the de-mapped bit data, and outputting the data. According to the method, the system frequency band utilization rate cannot be lost, the modulation signal power spectral density characteristic with fast out-of-band attenuation can be obtained by adding CPM mapping to the multi-carrier PSWF system input signal and changing the modulation index parameter, the peak-to-average power ratio of the existing multi-carrier PSWF modulation signal can be effectively reduced, signal distortion caused by a power amplifier is reduced. And the existing multi-carrier PSWF demodulation performance can be improved.