50 results about "Qam modulation" patented technology

The wireless transmission device includes a power amplifier that varies transmission power. An SNR degradation amount calculation unit calculates an SNR degradation amount {QAM} caused by QAM and an SNR degradation amount {APSK} caused by APSK on the basis of input / output characteristics of the power amplifier acquired from an input / output characteristic storage unit, a QAM modulated signal acquired from a QAM modulation unit, an APSK modulated signal acquired from an APSK modulation unit, and the transmission power of the power amplifier. A modulation scheme selection unit acquires a required SNR {QAM} of QAM and a required SNR {APSK} of APSK from a required SNR storage unit, compares “required SNR {QAM}+SNR degradation amount {QAM}” with “required SNR {APSK}+SNR degradation amount {APSK}”, and selects the modulation scheme with the smaller value.

The invention discloses a non-orthogonal multiple access system transmission method based on dual-frequency index modulation. According to the method, firstly, M-QAM modulation and dual-frequency index modulation of a specific system are respectively carried out on an input multi-user bit stream signal at a signal processing end of a base station, then OFDM-DFIM (Orthogonal Frequency Division Multiplexing-Distributed Frequency Index Modulation) modulation signals are generated by utilizing an orthogonal frequency division multiplexing technology, finally, channel conditions of all users are compared, power is allocated to all the users, and the signals are transferred to a time domain to be sent after superposition. Therefore, same-frequency simultaneous superposition transmission of signals of multiple users in a power domain is realized. And at a signal receiving end, performing signal separation by using a serial interference cancellation technology, and sequentially demodulating and restoring bit stream signals of each user through maximum likelihood estimation. According to the method, the spectrum efficiency is improved and the bit error rate is reduced by improving the proportion of the index information in all information, so that the system performance is further improved.

Networks operating at high frequencies in 5G and 6G may reduce the incidence of phase faulting by declaring that, above a specified frequency, messages are to be modulated according to multiplexed amplitude-phase modulation, instead of the QAM modulation generally used at lower frequencies. Multiplexed amplitude-phase modulation can provide larger phase margins than QAM of the same order, by arranging the modulation phase levels to be equally spaced-apart which they are not in QAM. For example, with 4 amplitude and 4 phase levels (16 states), the various modulation states can be separated by 90 degrees of phase, whereas in 16QAM the minimum phase separation is only 36.9 degrees, a serious problem at higher frequencies where phase noise predominates. In addition, QAM cannot accommodate non-square modulation tables, which are readily provided by amplitude-phase modulation, further enhancing fault-mitigation options.

The invention relates to the field of error vector magnitude calculation, in particular to a novel low-complexity error vector magnitude calculation method, which is used for simplifying EVM calculation of QAM (Quadrature Amplitude Modulation) of different orders, so that a redundant process generated in a judgment process during conventional calculation can be reduced, the processing speed is increased, and the processing efficiency is improved. The technical scheme comprises: determining a modulation type of a signal; performing normalization processing according to the modulation type of the signal; folding and translating the normalized signal; and judging whether the constellation image is equal to QPSK modulation or not, if so, calculating a signal EVM after folding transformation by adopting a calculation mode of a QPSK unit circle, otherwise, continuing to repeat folding and translation operations. The method is suitable for error vector magnitude calculation.

This invention relates to the field of unmanned aerial vehicle (UAV) communication technology, and in particular to a communication method for a dual-channel UAV line-of-sight (LAS) communication system. The method includes: acquiring communication quality, acquiring the optimal transmission frequency, acquiring the UAV's mission priority, transmitting video stream data, and performing multipath fading compensation steps. The method sets up high-frequency and low-frequency channels, calculates frequency quality indicators using signal-to-noise ratio (SNR), signal rate, and bit error rate (BER), and dynamically selects the optimal transmission frequency. Communication resources are allocated based on mission priority to ensure priority transmission of critical commands. Innovatively, differential geometry theory is used for multipath fading compensation, mapping the communication signal to a Riemannian manifold space, extracting fading features, and optimizing the processing. High- and low-frequency channel collaborative compensation is achieved, with mutual enhancement through received spectrum analysis and training sequence correction. Adaptive QAM modulation is supported, dynamically adjusting modulation parameters according to manifold curvature to construct a star-shaped multi-node communication network.

The application discloses a kind of adaptive QAM and OFDM bimodulus intracorporeal ultrasonic communication system and method based on channel estimation, belong to intracorporeal ultrasonic communication technical field, the transmitting end is configured with single carrier QAM modulation mode and multicarrier OFDM modulation mode, real-time evaluation intracorporeal ultrasonic channel quality in receiving end, according to the optimal modulation mode of evaluation result, according to the optimal modulation mode generation mode switching instruction, the mode switching instruction is sent to transmitting end, transmitting end according to the mode switching instruction seamlessly switches between single carrier QAM modulation mode and multicarrier OFDM modulation mode, so that transmitting end works in optimal modulation mode, the system and method can dynamically select optimal modulation mode according to intracorporeal channel real-time quality parameter, while ensuring that mode switching is reliably synchronized.

The application discloses a fast detection method based on regular hexagon modulation, which is suitable for regular hexagon QAM modulation in a communication system. The method comprises the following steps: constructing a communication system based on HQAM modulation, and configuring an additive white Gaussian noise (AWGN) channel; extracting HQAM modulation constellation point information and storing the information in a matrix form with axial coordinates as the matrix index; converting the signal through the AWGN channel into axial coordinates; searching in the information matrix by using the value of the axial coordinates; if the corresponding element exists in the matrix, symbol decision is performed; if the corresponding element does not exist in the matrix, it is judged whether the matrix indexes corresponding to the adjacent six hexagons exist in the information matrix; if the corresponding element still does not exist in the adjacent six hexagons, linear detection is used for symbol decision. The application provides a fast detection method based on regular hexagon modulation, so that symbol decision based on regular hexagon modulation can be more quickly and accurately detected.

The embodiments of the present application disclose a data transmission method, and an apparatus and a system thereof, which are compatible with the existing DSP framing schemes 400ZR+, 800ZR, and 800ZR+, are more conducive to hardware implementation, and can further be applied to future transmission scenarios using multi-wave or multi-subcarrier transmission, for example, 800 Gbps multi-subcarrier transmission using QPSK modulation, 1.2 Tbps multi-subcarrier transmission using 16-QAM modulation, 1.6 Tbps multi-subcarrier transmission using 16-QAM modulation, or even higher rate transmission scenarios such as 2.4 T / 3.2 T. The method comprises: sending W data frames, the number of symbols comprised in any one data frame in a polarization direction being 87552, each data frame comprising 12 subframes, and the number of symbols comprised in each subframe being 7296, where W is an even number.

The present invention provides a QAM modulation wireless communication method and system based on IM3. The wireless communication system includes a transmitting end and a receiving end. The transmitting end includes a transmitting signal source and a transmitting antenna connected in sequence. The receiving end includes a receiving antenna, a diode rectifier module, an IM3 modulator, a DC filter and a load. The IM3 modulator includes two branches connected in parallel between the signal transmission path and the ground line; an adjustable capacitor is provided on the first branch. An adjustable resistor is provided on the second branch. The present invention uses IM3 signals for communication, realizes zero energy consumption of wireless energy collaborative information transmission, reduces energy loss and prolongs system life, and is suitable for a variety of application environments. The present invention adopts a rectifier circuit with a single diode structure, and the IM3 signal used for transmission is generated by the diode itself, and does not require an additional oscillation circuit to generate it.

The invention relates to a semi-blind phase search method based on target planning in a probabilistic shaping CO-OFDM system. According to the method, a convergence area is set by taking an original constellation point after probability shaping as a center, and a hierarchical target planning strategy is adopted: a first layer takes maximization of signal points in the convergence area as a target, and a second layer takes minimization of a difference degree of probability distribution of a compensated signal and the original constellation point as a target. Meanwhile, test phases are selected by combining a staged test phase estimation strategy in the two-stage blind phase search algorithm, and the common phase noise is compensated by comparing the test phases. Simulation experiments show that compared with a traditional algorithm, the method can effectively suppress common phase noise of various constellation diagrams in different shapes under 16-QAM and 64-QAM modulation, the bit error rate performance is improved under the same signal-to-noise ratio, and meanwhile the spectrum utilization rate is remarkably improved.

The invention discloses an improved selective mapping scheme (N-SLM) for an orthogonal frequency division multiplexing non-orthogonal multiple access passive optical network (OFDM-NOMA PON), and relates to the technical field of optical communication and digital signal processing. In order to solve the problem that the peak-to-average power ratio (PAPR) of a downlink sending signal of a non-orthogonal multiple access system modulated by adopting OFDM is relatively high, and to overcome the defects that a traditional C-SLM scheme is high in calculation complexity and extra bandwidth resources need to be occupied due to the high error rate of explicit side information (SI), the invention provides a non-orthogonal multiple access method based on the C-SLM scheme. An N-SLM scheme is provided according to the characteristic of superposition transmission of power domain NOMA multi-user data on subcarriers. Compared with a C-SLM scheme, the scheme is low in calculation complexity and does not need to send explicit SI. The method mainly comprises the generation process of alternative OFDM-NOMA signals of a sending end and the demodulation process of a receiving end. According to the invention, the sending end adopts information bit cyclic shift, and inserts very few check bits subjected to repeated coding in a leading part to generate a plurality of pieces of alternative bit information, so that explicit transmission of SI is avoided. And performing QAM modulation, power distribution and OFDM modulation on all the alternative bit information in sequence to generate a plurality of groups of OFDM signals with different power levels, and performing permutation, combination and linear superposition on the OFDM signals to synthesize a plurality of alternative OFDM-NOMA signals. And calculating the PAPR values of all the alternative OFDM-NOMA signals, and selecting the alternative OFDM-NOMA signal with the minimum PAPR to carry out subsequent signal processing. And a receiving end respectively performs soft demodulation and hard demodulation on QAM symbols corresponding to the repeatedly coded check bit and the information bit, and performs corresponding reverse cyclic shift on the received information bit according to the check bit which is judged to be output after repeated decoding. And after serial interference cancellation (SIC) is carried out on the low-power-level data to obtain corresponding information, the same processing process is carried out.

The present disclosure proposes a transmitter and receiver for medical applications, wherein the transmitter comprises: an analog front end for receiving an analog signal of a neural electrode; a digital baseband processing module for digitizing and channel coding the analog signal to obtain a coded signal; a modulator for 16-QAM modulation of the coded signal to obtain a modulated signal; 16-QAM modulation is used to improve the scalable data rate; a plurality of target frequency signals are generated by a phase-locked frequency divider, and the target frequency signals are divided into a plurality of target sub-frequency signals; the phase of the modulated signal is adjusted based on the plurality of target sub-frequency signals to obtain a phase-adjusted signal, realizing multi-band data transmission within the transmitter; and finally a power amplifier amplifies the phase-adjusted signal, and the amplified phase-adjusted signal is transmitted to a transmitting unit so that the transmitting unit transmits a signal, realizing high-speed and low-power signal transmission.

One disclosure of the present specification provides a user equipment (UE). The UE comprises: a transceiver for transmitting a signal and receiving a signal; and a processor for controlling the transceiver, wherein the processor: obtains network signal (NS) 52; determines an additional maximum power reduction (A-MPR) configured on the basis of obtained NS 52; and determines a transmission power for a sidelink signal, on the basis of the determined A-MPR, the transceiver transmits, to another UE, the sidelink signal with the transmission power, the sidelink signal is transmitted within a band having a center frequency of 5885 MHz and a bandwidth of 40 MHz, and the A-MPR is configured on the basis of region 1, region 2, and region 3, and may be configured on the basis of QPSK, 16 QAM, 64 QAM, and 256 QAM modulation schemes.

The application is an improved selective mapping scheme (N-SLM) for an orthogonal frequency division multiplexing non-orthogonal multiple access passive optical network (OFDM-NOMA PON), and relates to the technical fields of optical communication and digital signal processing. In order to solve the problem of high peak-to-average power ratio (PAPR) of downlink signals in a non-orthogonal multiple access system using OFDM modulation, aiming at the shortcomings of high computational complexity of a traditional selective mapping (C-SLM) scheme and high error rate of explicit side information (SI) requiring additional bandwidth resources, the N-SLM scheme is proposed according to the characteristics of superimposed transmission of power domain NOMA multi-user data on subcarriers. Compared with the C-SLM scheme, the scheme has low computational complexity and does not need to send explicit SI. The application mainly includes the generation of alternative OFDM-NOMA signals at the sending end and the demodulation process at the receiving end. The sending end adopts information bit cyclic shift and inserts a few repeated coded check bits in the preamble part to generate multiple alternative bit information, thereby avoiding the explicit transmission of SI. All alternative bit information is sequentially subjected to QAM modulation, power allocation and OFDM modulation to generate multiple groups of OFDM signals with different power levels, which are arranged and combined to linearly superimpose multiple alternative OFDM-NOMA signals. The PAPR values of all alternative OFDM-NOMA signals are calculated, and the alternative OFDM-NOMA signal with the minimum PAPR is selected for subsequent signal processing. The receiving end respectively performs soft demodulation and hard demodulation on the QAM symbols corresponding to the repeated coded check bits and information bits, and performs corresponding reverse cyclic shift on the received information bits according to the check bits output by the repeated decoding. After the low-power-level data is subjected to successive interference cancellation (SIC) to obtain the corresponding information, the same processing process is performed.

The invention discloses a QAM-OFDM (Quadrature Amplitude Modulation-Orthogonal Frequency Division Multiplexing)-based communication method and device, and relates to the technical field of ultrasonic communication, and the method comprises the following steps: using a convolutional code for an original signal to obtain an initial signal, converting the initial signal into a modulation signal by using a QAM modulation technology, and converting the modulation signal into an analog signal by using an OFDM modulation technology; performing a spread spectrum technology on the analog signal, and performing signal processing on the spread spectrum analog signal by using a power amplifier and a band-pass filter; receiving an analog signal which is transmitted by a steel rail channel and is subjected to signal processing; and performing signal conversion on the received signal by using an analog-to-digital converter, demodulating the converted signal by using an OFDM demodulation technology, and restoring the demodulated signal into an original signal by using a QAM demodulation technology. According to the invention, signal anti-interference capability can be enhanced, and high-efficiency signal transmission can be maintained.

The present invention relates to the field of error vector magnitude calculation, and specifically to a novel low-complexity error vector magnitude calculation method, which simplifies the EVM calculation of QAM modulations of different orders, thereby reducing the redundant processes generated during the judgment process during conventional calculations, improving processing speed, and improving processing efficiency. The technical solution includes: determining the modulation type of the signal; performing normalization processing according to the modulation type of the signal; folding and translating the normalized signal; determining whether the constellation image is equivalent to QPSK modulation, and if so, calculating the EVM of the signal after folding and transformation using the QPSK unit circle calculation method, otherwise continuing to repeat the folding and translation operations. The present invention is suitable for error vector magnitude calculation.

The application provides a joint time-frequency domain equalization method under PSK and QAM modulation, which comprises the following steps: receiving an initial signal, sampling, obtaining an initial head scattered pilot, processing the initial head scattered pilot, realizing time domain cross-correlation and autocorrelation, respectively performing fast Fourier transform on a first processed signal and a second processed signal to obtain a third processed signal and a fourth processed signal, taking the third processed signal as a numerator and the fourth processed signal as a denominator to obtain a channel estimation frequency response, estimating a signal-to-noise ratio of the second processed signal to obtain a signal-to-noise ratio curve, calculating a signal-to-noise ratio estimation value according to a peak value in the signal-to-noise ratio curve and data variance calculated according to other data, combining the channel estimation frequency response to obtain a frequency domain equalization coefficient, processing second data and a tail scattered pilot in the initial signal to obtain a fifth processed signal, and combining the frequency domain equalization coefficient to obtain a time domain signal.

The invention relates to the technical field of digital transmitters, in particular to a digital millimeter wave transmitter which comprises a coupler, an orthogonal digital modulator and a digital-analog mixed mode Doherty power amplifier. Wherein the coupler is used for generating a broadband orthogonal signal and inputting the broadband orthogonal signal into the orthogonal digital modulator so as to realize QAM (Quadrature Amplitude Modulation) of the broadband orthogonal signal, and the orthogonal digital modulator inputs the modulated broadband orthogonal signal into the digital-analog mixed mode Doherty power amplifier so as to carry out power amplification on the modulated signal. According to the digital millimeter wave transmitter, through collaborative design of digital modulation and the mixed mode Doherty power amplifier, high system efficiency is achieved under the conditions of high peak-to-average ratio and high-power output, energy consumption is remarkably reduced, a quadrature amplitude modulation (QAM) modulation precision and signal linearity are improved by adopting the quadrature digital modulator and a precise amplitude / phase control mechanism, and the digital millimeter wave transmitter has the advantages of being simple in structure, low in cost and high in reliability. And high-speed data transmission is supported, and the requirement of a 5G system for high-capacity communication is met.

The invention relates to a signal phase keeping method and system in optical fiber communication, when coherent detection of received signals is carried out, the received signals are balanced in combination with frequency offset estimation (FOE), carrier phase recovery (CPR) and a plurality of neural networks, the carrier phase recovery is realized based on a Viterbi-Viterbi algorithm, and meanwhile, the plurality of neural networks provided by the invention can be used for carrying out coherent detection on the received signals. An input value, a neural node and an output value are complex numbers, and in a wireless channel equalization network, a CReLU activation function is used for complex value calculation for the first time. Compared with the prior art, the method is suitable for a complex signal generated by a QAM modulation format or coherent detection, the bit error rate performance more reliable than that of a real number neural network is achieved, and the method has the advantages of being low in complexity, reliable in bit error rate performance, high in sensitivity and the like.

Embodiments of the present application relate to the technical field of channel blind equalization, and particularly to a high-order QAM blind equalization method based on a cognitive communication system, comprising: constructing a system model of the cognitive communication system, the cognitive communication system using high-order QAM modulation; constructing a cost function for the first phase of the cognitive communication system under a high-order QAM modulation channel and an iterative formula for blind equalization in the first phase, optimizing the blind equalizer to optimize and minimize the cost function of the first phase; determining a switching threshold, and switching to the second phase when the function value of the cost function of the first phase is less than or equal to the switching threshold; constructing a cost function for the second phase of the cognitive communication system under a high-order QAM modulation channel and an iterative formula for blind equalization in the second phase, optimizing the blind equalizer to optimize and minimize the cost function of the second phase. This method effectively improves the convergence stability, convergence speed, and equalization quality of high-order QAM blind equalization.

The invention relates to a public phase error compensation method based on projection thermodynamic diagram assistance (PHM) in a coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. According to the method, rotation and divergence three-dimensional projection thermodynamic diagram distribution characteristics, caused by phase noise, of signal points in a constellation diagram of a receiving end are analyzed, a convergence area is set with an original constellation point as the center for target optimization, and the optimal compensation phase is determined by counting the maximum number of the signal points in the convergence area. In combination with a staged test phase estimation strategy in a two-stage blind phase search (BPS) algorithm, the calculation complexity is reduced, and the compensation precision is improved at the same time. Simulation experiments show that compared with a traditional method, the method can effectively suppress common phase noise of various constellation diagrams in different shapes under 16-QAM modulation, the bit error rate performance is better under the same signal-to-noise ratio, and the spectrum utilization rate is remarkably improved.

The application discloses a kind of non-orthogonal multiple access system transmission methods based on dual-frequency index modulation.The method is first in the signal processing end of base station to the input multi-user bit stream signal respectively carries out specific M-QAM modulation and dual-frequency index modulation, then generates OFDM-DFIM (Dual Frequency Index Modulation) modulation signal using orthogonal frequency division multiplexing technology, finally compares the channel conditions of each user, and allocates power for each user, and is superimposed after being sent to time domain.Thus, the signal of multiple users is transmitted simultaneously in the same frequency domain in the power domain.In the signal receiving end, signal separation is carried out using serial interference cancellation technology, and then the bit stream signal of each user is demodulated and restored in turn by maximum likelihood estimation.The method improves the proportion of index information in the total information, thereby improving the spectral efficiency and reducing the bit error rate, thereby further improving the system performance.

The invention discloses a beneficial interference precoding solving method and system based on symbol-level extrapolation, and belongs to the technical field of wireless communication, and the solving method comprises the steps: extrapolating a precoding matrix of an mth time slot by using a precoding matrix corresponding to an nth symbol time slot in the same transmission block, obtaining a closed-form solution structure of a beneficial interference precoding matrix of symbol-level extrapolation; based on the closed-form solution structure of the beneficial interference precoding matrix of symbol-level extrapolation, a phase scaling criterion under PSK modulation and a symbol scaling criterion under QAM modulation are combined, and the closed-form solution structure of the precoding matrix under the total transmitting power constraint is obtained; and solving a scaling coefficient corresponding to the symbol time slot, and substituting the scaling coefficient into the closed-form solution structure of the precoding matrix to obtain the precoding matrix. According to the method, the precoding matrixes of different symbol time slots are extrapolated by utilizing the mathematical relationship among different time slot symbols in a transmission block, a large amount of calculation is avoided, PSK modulation and QAM modulation are considered at the same time, and the time complexity is low.

The invention relates to the technical field of unmanned aerial vehicle communication, in particular to a communication method of a dual-channel unmanned aerial vehicle line-of-sight communication system, which comprises the steps of acquiring communication quality, acquiring an optimal transmission frequency point, acquiring task priority of an unmanned aerial vehicle, transmitting video stream data and executing multipath fading compensation. Calculating a frequency point quality index through a signal-to-noise ratio, a signal rate and an error rate, and dynamically selecting an optimal transmission frequency point; allocating communication resources based on task priorities to ensure that key instructions are transmitted preferentially; a differential geometry theory is innovatively adopted to carry out multipath fading compensation, communication signals are mapped to a Riemannian manifold space, and fading features are extracted and optimized; cooperative compensation of high and low frequency channels is realized, and mutual enhancement is realized through receiving spectrum analysis and training sequence correction; and adaptive QAM modulation is supported, modulation parameters are dynamically adjusted according to manifold curvature, and a star-shaped multi-node communication network is constructed.

The application discloses a communication method and device based on QAM-OFDM, relates to the technical field of ultrasonic communication, and comprises the following steps: using convolution code on an original signal to obtain an initial signal, using QAM modulation technology on the initial signal to convert the initial signal into a modulated signal, and using OFDM modulation technology to convert the modulated signal into an analog signal; using spread spectrum technology on the analog signal, and using a power amplifier and a band-pass filter to process the analog signal; receiving the analog signal processed by a steel rail channel; using an analog-digital converter to convert the received signal, using OFDM demodulation technology to demodulate the converted signal, and using QAM demodulation technology to restore the original signal from the demodulated signal. The application can enhance the anti-interference capability of the signal while maintaining efficient signal transmission.

The application discloses a kind of LDPC decoding method based on bidirectional circulation network, belong to communication technical field, including: the 1024QAM signal after transmission by coherent optical system is collected;Discrete channel quantizer suitable for high-order modulation signal is constructed;All bit information is calculated and the uniformity of bit information is completed;Bidirectional information bottleneck decoder is constructed based on bidirectional circulation structure, the check node design of bidirectional information bottleneck decoder;Variable node design of bidirectional information bottleneck decoder.The method utilizes multivariate parameter to construct information bottleneck framework, for all M-QAM modulation format, only need to construct two LUTs extra, can solve the problem that memory requirement increases with modulation order in IB decoding method.In addition, we use bidirectional circulation network and the symmetry of quantized information to realize the multiplexing of table, give full play to the role of intermediate information, make the relationship between the number of LUT search and node degree in IB decoding algorithm from square magnitude to linear magnitude.

The invention discloses an intelligent reconfigurable wireless communication physical layer architecture and a dynamic configuration method, which are characterized in that deep fusion of dynamic partial reconstruction and online machine learning is realized through software and hardware collaborative design based on an ARM + FPGA (Field Programmable Gate Array) architecture. The architecture supports dynamic switching of OFDM waveforms and a QPSK / 16-QAM modulation mode, and channel selection is optimized in real time by using an MAB algorithm. And efficient wireless channel selection, adaptive modulation and dynamic hardware reconfiguration are realized. According to the architecture, communication parameters can be adjusted in real time in a dynamically changing wireless environment, the system throughput is improved, and the bit error rate is reduced.

The invention provides a wireless communication link high-fidelity simulation method for a high-dynamic Internet of Vehicles, which comprises the following steps of: performing channel modeling by using a channel simulation platform according to an input network layout, a terminal track, a propagation scene and an antenna mode to generate a time-varying channel coefficient; accurate modeling is carried out on key physical phenomena such as multipath propagation, Doppler frequency shift, path gain and propagation time delay in the Internet of Vehicles, and high-fidelity simulation of channel dynamic change characteristics in a high-mobility scene is realized; a transmitter class object, a receiver class object and a channel class object are constructed based on an object-oriented thought, a plurality of processing modules such as QAM modulation, multi-carrier modulation, pilot frequency design, channel estimation and equalization, frequency offset correction and the like are supported, and good transportability and expansibility are achieved. According to the invention, high-fidelity Internet of Vehicles communication system simulation is realized, a communication transceiver signal processing flow is included, and an efficient fidelity verification platform is provided for design and test of an Internet of Vehicles communication protocol and algorithm.

The invention discloses a calibration method of a power amplifier for high-order QAM (Quadrature Amplitude Modulation) modulation signal input. Calibration data is generated for a power amplifier using an input signal of a low-order or medium-order modulation scheme. When the power amplifier is calibrated, whether an input signal of the power amplifier is a modulation signal in a high-order QAM modulation mode or not is judged. And if not, the switching point of every two adjacent gain modes is kept unchanged by the rate amplifier. And if yes, the power amplifier adjusts the switching point of every two adjacent gain modes downwards. According to the invention, the EVM (Error Vector Magnitude) of the power amplifier near the switching point of the adjacent gain modes is reduced, and meanwhile, the power consumption of the power amplifier is not obviously increased.

The invention discloses an orthogonal time-frequency-space transceiver suitable for a satellite-ground scene, and relates to the technical field of satellite communication, in particular to the orthogonal time-frequency-space transceiver suitable for the satellite-ground scene. The invention aims to solve the problem that the bit error rate is too high. The method comprises the following steps of: 1, enabling transmission data to sequentially pass through a convolutional coding module, an interleaving module, a scrambling module, a QAM (Quadrature Amplitude Modulation) module, an OTFS (Over the Top File System) module and a CP (Content Program) adding module, and inserting DMRS (Demodulation Reference Signal) into output data of the 2, framing a data symbol, an information symbol and a leader sequence; 3, the framed data sequentially pass through a DAC and an antenna to enter a time-frequency double-selection channel, an antenna on the other FPGA receives a signal, then the signal passes through an ADC to reach a frame synchronization module, output data are sequentially input into CFO frequency offset estimation and correction, symbol synchronization, CP removal, FFT, channel estimation and equalization, inverse two-dimensional Fourier transform, information symbol solution, QAM demodulation, descrambling, de-interleaving and de-convolution coding modules, and then the output data are sent to a frame synchronization module. And the received 01 sequence is obtained.