230 results about "QAM" patented technology

A disclosure of the present specification provides a user equipment (UE). The UE comprises: a transceiver unit for transmitting or receiving a signal; and a processor for controlling the transceiver unit, wherein: the transceiver unit may include two transmitters; the UE may have a maximum output of 29 dBm; the processor may determine transmission power on the basis of a configured maximum power reduction (MPR); the MPR may be configured on the basis of edge RB allocations, outer RB allocations, and inner RB allocations; the MPR may be configured on the basis of DFT-s-OFDM and CP-OFDM, the MPR may be configured on the basis of Pi / 2 BPSK, QPSK, 16 QAM, 64 QAM, and 256 QAM; and the transceiver unit may transmit a signal to a base station by using the two transmitters on the basis of the determined transmission power.

The present invention discloses an unified multiple access (MA) based system for uplink transmission of data by multiple users. The system comprises an user interface integrated transmitter modules for transmitting the data from multiple user transmitters over waveforms through a cooperative unified data grid structure including grid points, said unified data grid structure including each user transmitter allocation of a few non-overlapping grid points for loading respective data bearing symbols, with zeros loaded onto unallocated grid points. The user transmitter is configured to transmit a sparsely loaded grid resembling to the unified two-dimensional data grid structure involving data-bearing Quadrature Amplitude Modulation (QAM), where a part of available grid points of the grid as allocated is loaded with QAM symbols and remaining grid points are loaded with zero symbols. A waveform modulator corresponding to user transmitter is also provided in the present system for waveform modulation of said sparsely loaded grid as per the waveforms enabling transmission for multi-antenna reception of the waveforms to a base station or an access point.

Provided are a communication method and a communication device, the method comprising: determining a transmission waveform of a signal, the transmission waveform being related to a threshold of a first parameter, the first parameter comprising: a modulation order and a roll-off factor, the transmission waveform is an orthogonal frequency division multiplexing QAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of orthogonal amplitude modulation or an orthogonal frequency division multiplexing OQAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of offset orthogonal amplitude modulation, and the roll-off factor is determined based on the transmission bandwidth and the number of symbols carried by the transmission waveform. And transmitting or acquiring the signal. In the method provided by the invention, the network equipment or the terminal equipment can determine the transmission waveform of the signal according to the set threshold value of the modulation order and the threshold value of the roll-off factor, so that the output power supporting higher power amplifiers can be obtained, and a larger signal coverage range can be obtained.

The invention discloses a multipath effect suppression method for 2.4 GHz radio frequency identification. The multipath effect suppression method comprises a transmitting end processing flow and a receiving end processing flow. A transmitting end carries out pulse code modulation on an analog signal to obtain a digital signal, blocks the digital signal after channel coding, and distributes the digital signal to subcarriers through quadrature amplitude modulation; and generating a time domain OFDM symbol through IFFT (Inverse Fast Fourier Transform), adding a cyclic prefix and a synchronization head, converting into an analog baseband signal, and performing up-conversion, filtering, amplification and radiation. The receiving end amplifies the signal, down-converts the signal to a baseband, filters the signal and converts the signal into a digital signal; the method comprises the following steps of: synchronizing header frame alignment, recovering a coding bit stream through FFT (Fast Fourier Transform) and QAM (Quadrature Amplitude Modulation) demodulation, carrying out CRC (Cyclic Redundancy Check) after decoding and merging, returning ACK (Acknowledgement Character) if According to the method, the multipath effect can be effectively inhibited, and the integrity of received data is improved.

This application provides a communication method, apparatus, and system, to increase a data transmission rate of a terminal device using a DFT-S-OFDM waveform when a single uplink CC is used in a CA scenario. The communication method, apparatus, and system may be applied to a 5G system, a future communication system such as a 6G system, and other fields. The method includes: sending first indication information to the terminal device when a first condition is satisfied, and receiving data from the terminal device by using the DFT-S-OFDM waveform and a first modulation scheme. The first condition includes: There is one component carrier used by the terminal device to perform uplink data transmission in the carrier aggregation CA scenario. The CA scenario includes that CA is configured for uplink and / or CA is configured for downlink. The first indication information indicates to use the DFT-S-OFDM waveform and the first modulation scheme to perform uplink transmission. The first modulation scheme includes 16 quadrature amplitude modulation QAM or 64 QAM.

The invention discloses a signal transmission method, a signal receiving method, a channel sending end and a channel receiving end, and belongs to the technical field of communication, and the signal transmission method comprises the steps: obtaining to-be-sent original data, and generating a bit encryption factor, a constellation encryption factor, a bit disturbance factor and a constellation disturbance factor; the method comprises the following steps: dividing original data to be sent into even number of data blocks according to a preset rule to construct a complete binary tree, and carrying out first traversal encryption and primary disturbance on the data blocks by utilizing a bit encryption factor; converting the data block subjected to primary perturbation into a parallel bit stream through serial-parallel conversion, performing QAM mapping on the parallel bit stream, and performing second traversal encryption and second perturbation according to a constellation perturbation factor; the parallel bit streams after secondary disturbance are converted into serial signals through a discrete Fresnel inverse transformation matrix and parallel-serial conversion; and performing up-conversion processing on the serial signal and transmitting the serial signal to a transmission channel. According to the invention, the problem of insufficient safety protection in practical application in the prior art is solved.

A quadrature amplitude modulation (QAM) transmitter separates an input digital level into I and Q components. In a variation, a QAM transmitter uses every other input digital level as an I or Q component. A QAM receiver receives a QAM modulated signal and outputs digital levels. A QAM transmitter for transmitting analog levels uses a pair of input analog levels as the I and Q components. A QAM receiver receives a QAM modulated signal and outputs analog levels. The digital and analog input levels are produced by encoding N samples using L orthogonal codes.

Systems and devices are provided for receiving or transmitting IQ data (e.g., suitable for passband quadrature amplitude modulation (QAM)) over a wireline using pairs of baseband pulse amplitude modulation (PAM-n) signals. Encoding circuitry may map data from an input bit stream to IQ data that includes an in-phase component and a quadrature-phase component. Modulator circuitry may determine an in-phase PAM-n signal based on the in-phase component and a quadrature-phase PAM-n signal based on the quadrature-phase component. Driver circuitry may transmit the in-phase PAM-n signal and the quadrature-phase PAM-n signal across a wireline channel. The in-phase PAM-n signal may be different by 90° from the quadrature-phase PAM-n signal. This may enable a remote receiver on the wireline channel to detect the in-phase PAM-n signal independently of the quadrature-phase PAM-n signal.

A method of a second communication node may comprise: obtaining a compensated first reception signal by performing channel estimation between a first communication node and a second communication node for a first transmission signal received from the first communication node; obtaining an offset-demodulated signal and a first demodulated bit sequence by performing offset-demodulation on the first reception signal; obtaining a frequency-domain signal by performing time-to-frequency domain transform on the offset-demodulated signal; obtaining a complex signal sequence by performing subcarrier deallocation on the frequency-domain signal; obtaining a second demodulated bit sequence by performing QAM demodulation on the complex signal sequence according to the first demodulated bit sequence; and obtaining a final demodulated bit sequence by performing reassembly on the first demodulated bit sequence and the second demodulated bit sequence.

A UE of a wireless communication network first receives a modulation and coding scheme index IMCS for demodulating a physical layer data channel of the network. The UE then demodulates the physical layer data channel with a non-square quadrature amplitude modulation (NS-QAM) having a modulation order and code rate corresponding to a spectral efficiency (SPEFF) substantially equal to a SPEFF of a square QAM (S-QAM) SPEFF indicted by the IMCS, where the NS-QAM has an effective channel code rate no larger than the code rate for which the UE may skip decoding a transport block in an initial received transmission.

The invention provides an interleaving method in channel coding and a communication device thereof. The degree of a variable node is considered when a to-be-interleaved code word sequence is interleaved. Based on the conception of interleaving according to degree, the energy levels of bits in a code word sequence obtained after interleaving and bit positions contained in a QAM symbol meet the condition that a column with a large column weight corresponds to the bit position of a low energy level of the QAM symbol, and a column with a small column weight corresponds to the bit position of a high energy level of the QAM symbol. And the interleaving complexity can be further simplified on the basis. According to the interleaving method, the hardware complexity of interleaving can be reduced, and meanwhile, the interleaving performance superior to that of row-column interleaving can be obtained.

The invention relates to the technical field of ultrahigh-order QAM (Quadrature Amplitude Modulation) signal nonlinear compensation, in particular to an ultrahigh-order QAM signal nonlinear compensation method and system based on a time characteristic memory neural network, and the method comprises the steps: S1, obtaining a plurality of groups of orthogonal amplitude modulation signals under the condition of different optical signal-to-noise ratios, performing zero mean normalization processing on the quadrature amplitude modulation signal to obtain a pre-processed quadrature amplitude modulation signal; s2, dividing the preprocessed orthogonal amplitude modulation signal into a training set and a test set, constructing a signal nonlinear compensation model, and training the signal nonlinear compensation model by using the training set to obtain a trained signal nonlinear compensation model; and S3, based on the trained signal nonlinear compensation model, performing nonlinear compensation on a quadrature amplitude modulation signal to be compensated. According to the method, the time sequence characteristics of the signals can be extracted, the two-way time dependence relation can be captured, and the purpose of nonlinear distortion compensation is achieved.

Aspects of the present application provide methods and devices for a phase tracking reference (PT-RS) scheme for use by a single carrier Offset QAM (SC-OQAM) transmitter and receiver to estimate, and correct, phase errors that occur over the communication link between the SC-OQAM transmitter and receiver. A transmitter may set the sign (positive or negative) of PT-RS symbols dynamically allowing the transmitter to better utilize IQ interference caused by data symbols and other PT-RS symbols. Another aspect of the present disclosure provides a receiver that can estimate phase error due to phase noise without knowing the sign of PT-RS symbol or the sign of IQ interference. This type of phase error estimation improves the phase noise estimation performance, and thus may improve the overall block error rate (BLER) performance at the receiver.

An apparatus may include a transmitter and one or more processors configured to identify a code rate of a low-density parity-check (LDPC) code, receive, by an LDPC encoder, a set of information bits and encode, using the code rate, the set of information bits to generate a set of encoded bits and a set of parity bits, generate, from the set of encoded bits, a matrix of bit arrays, discard one or more parity bits from the set of parity bits to generate a parity bit array with a size equal to a number of column of the matrix, generate a bit array by concatenating (1) one or more bit arrays selected from the matrix of bit arrays and (2) one or more bits selected from the parity bit array corresponding to the one or more bit arrays, and modulate, by a modulator, the bit array to generate modulated data.

An improved non-OFDM communication system and method replaces an FFT at the receiver with an alternative processing configuration. The use of dense subcarriers and assigning A, B pairs based upon a pre-assigned QAM bit-mapped constellation will be maintained as with traditional OFDM. However, the receiver sample-rate is independent of subcarrier frequency-separation, and the system does not maintain separate real and imaginary signals at the transmitter and receiver. The system also processes receiver samples incrementally without awaiting the end of the modulation cycle, and uses incrementally-processed data to characterize disruptions introduced by the channel so as to better adapt to these disruptions. The system has the potential to increase signal throughput by a factor of two by re-using one of the freed-up information paths previously used by the real and imaginary signals.

A network node (710A, 710B) configures a user equipment, UE (712A, 712B), with a modulation to be used for a narrowband physical downlink shared channel, NPDSCH, in a downlink pilot time slot, DwPTS, in a special subframe in time division duplex, TDD, narrowband internet of things, NB-IoT. The network node configures the UE with a special subframe configuration for the special subframe. The special subframe configuration is selected from among special subframe configurations 1, 2, 3, 4, 6, 7 and 8, if the modulation is 16 quadrature amplitude modulation, 16-QAM.

The invention relates to the technical field of underwater acoustic communication, in particular to an underwater high-speed underwater acoustic communication signal modulation and demodulation method based on multi-beam diversity, which comprises the following steps of: modulating at a transmitting end, generating a space-time coded modulation signal by adopting a multi-beam transducer array, and realizing space diversity by a receiving end through self-adaptive beam forming; modulation adopts a hybrid mode of combining orthogonal frequency division multiplexing and 256-QAM, and the spectrum efficiency is optimized through dynamic subcarrier allocation; and a receiving end demodulates, a three-dimensional compensation matrix is constructed based on an LSTM-CNN joint network, and joint estimation of channel impulse response and Doppler frequency offset is realized. According to the invention, by adopting an eight-unit cross array type multi-beam diversity technology, space signal focusing and multipath interference suppression tasks are completed, and the effect of spatial multiplexing gain is achieved; through combination of 256-QAM and OFDM dynamic subcarrier distribution, a high-spectrum-efficiency transmission task is completed; a time delay-Doppler joint estimation task is completed by constructing a three-dimensional compensation matrix of an LSTM-CNN joint network, so that the channel estimation error is reduced.

Disclosed is a method comprising, by a transmitter apparatus, partitioning (901) an input data stream to obtain a bit stream X1 and a bit stream X2; subjecting (902) the bit stream X2 to encoding by LDPC encoders, to obtain X2 parity bits, and X2 information bits; applying (903) SPC encoding to the X2 parity bits, together with the bit stream X1, to obtain sign bits, wherein the bit stream X1 is used as padding bits; subjecting (904) the sign bits, the padding bits, and the X2 information bits, to an interleaver operation to obtain an interleaver output; subjecting (905) the interleaver output to Gray mapping to form multiple consecutive quadratic amplitude modulation, QAM, symbols; modulating (905) the QAM symbols by quadratic amplitude modulation to obtain a modulated data stream; and transmitting (906) the modulated data stream via a radio access network or optical fibre communication network.

In an example, a system includes a receiver configured to receive a differential input signal from a quadrature amplitude modulation (QAM) transmitter at a differential interface that includes a first input and a second input. The system also includes a first switch coupled to the first input and a second switch coupled to the second input, where the first switch and second switch are configured to couple the first input and the second input to a complex mixer in a non-inverting configuration. The system includes a third switch coupled to the first input and a fourth switch coupled to the second input, where the third switch and the fourth switch are configured to couple the first input and the second input to the complex mixer in an inverting configuration. The complex mixer is configured to produce an output signal based on the non-inverting configuration and the inverting configuration.

The present invention discloses a communication system including WLAN communication systems comprising transmitter including an OTFS grid based Orthogonal Time Frequency Space (OTFS) waveform generator and Multiple Input Multiple Output (MIMO) streams. The transmitter comprises signal processor including OTFS modulator having FEC (forward error correction) encoder for pre-FEC bit appended input data stream and transmission of encoded input data stream in a selective sequence vide OTFS waveform modulated OTFS grid-partially loaded with QAM / PSK symbols of said encoded input data stream through MIMO transmitter and receiver streams including MIMO pre-coder based multi antenna support for said transmission and reception of said OTFS waveform thereby enabling OTFS waveform transmission and retrieval of input data stream.

In one aspect, a method described herein can be used for laser carrier recovery in optical coherent communication systems utilizing quadrature amplitude modulation (QAM) at a receiver. The method includes receiving, at the receiver, a transmitted signal modulated using QAM and a local oscillator (LO) signal. The method includes detecting, at the receiver, a phase offset between the transmitted signal and the LO signal. The method includes compensating, at the receiver, by generating an error signal based on the average power and / or voltage difference between the In-phase (I) and Quadrature-phase (Q) paths of the received signal at the receiver, where the error signal compensates for the phase offset between the transmitted signal and the LO signal.

Access to FR2 (high frequency bands) is essential for anticipated high-demand networking in 5G-Advanced and 6G systems. Unfortunately, phase noise is an unavoidable barrier, greatly limiting message reliability. Therefore, a low-cost solution is provided in which the transmitter (either base station or user device) transmits a special phase-tracking reference signal consisting of zero amplitude in one branch, and a predetermined non-zero amplitude in the other branch. For example, in QAM, the I-branch may be powered according to the maximum branch amplitude of the modulation scheme, and the Q-branch may have zero amplitude as transmitted. The receiver, on the other hand, generally measures a non-zero amplitude in the received Q branch due to phase noise, which rotates the I and Q branches into each other. The receiver can then determine the phase rotation angle precisely by measuring the non-zero amplitude in the Q branch, negating phase noise at negligible cost.

DFT spreading is applied to a sequence of symbols to generate a DFT-spread sequence of symbols. The DFT-spread sequence of symbols is frequency-division multiplexed with a reference signal sequence to generate a multiplexed sequence, and the DFT-spread sequence of symbols and the reference signal sequence are recoverable from demultiplexing the multiplexed sequence. Further processing, such as a transform to convert to time domain and / or spectral shaping, may be applied in some embodiments. The symbols may be modulation symbols to which data bits are mapped, in binary phase-shift keying (BPSK) modulation, pi / 2-BPSK modulation, quadrature phase-shift keying (QPSK) modulation, quadrature amplitude modulation (QAM) or offset-QAM (OQAM), for example. Embodiments may be applied in conjunction with any of different types of reference signals, such as a demodulation reference signal (DM-RS), a phase tracking reference signal (PT-RS), or a channel state information reference signal (CSI-RS), or different types of reference signal sequences.

The invention discloses an ultrahigh-order DSM coding mapping method and system based on a three-dimensional constellation, and belongs to the technical field of Delta-sigma modulation. The mapping method comprises the following steps: performing three-dimensional constellation mapping on bit data, performing dimension reduction processing to obtain a two-dimensional constellation, and obtaining a QAM signal; performing inverse Fourier transform on the obtained QAM signal, and converting a frequency domain signal into a time domain signal; dSM modulation is carried out on the time domain signal, then a low-frequency signal and high-frequency noise are cut off through a low-pass filter, and a DSM signal is output; after the DSM signal is transmitted through a channel, reversely converting the two-dimensional constellation into the three-dimensional constellation again; judging and demodulating the three-dimensional constellation to obtain bit data; according to the method, DSM modulation is carried out on the time domain, the effective resolution of signals and the anti-interference capability of the signals to noise are improved, in constellation mapping, a three-dimensional constellation is used for replacing a two-dimensional constellation, the Euclidean distance between constellation points is increased, and the influence of quantization noise on the signals in DSM modulation is reduced.

The invention discloses a WiFi-to-LoRa long-distance transmission method based on cross-protocol communication, and the method comprises the steps: carrying out the up-sampling and cyclic prefix removal of a simulated LoRa signal, carrying out the calculation of a LoRa sub-signal through an FFT algorithm, obtaining a frequency domain component of a corresponding bandwidth, and determining a to-be-used OFDM sub-carrier; selecting the closest constellation point to replace the deviated frequency domain component, and zeroing other constellation points except the constellation point corresponding to the effective subcarrier to complete QAM decoding of the LoRa signal; converting the symbols after QAM decoding into bit data, performing convolutional coding on the bit data, grouping the bit data according to preset bits, and performing QAM coding to generate corresponding QAM symbols; a plurality of QAM symbols are distributed to OFDM subcarriers at the same time, frequency domain components are converted into time domain signals through inverse Fourier transform, and long-distance transmission is carried out. According to the invention, long-distance transmission from WiFi to LoRa can be realized.

Various aspects of the present disclosure generally relate to wireless communication. Some aspects more specifically provide procedures and configurations used to perform, at a transmitter, probabilistic amplitude shaping (PAS) of quadrature amplitude modulation (QAM) communications using non-binary polar coding (NBPC). NBPC differs from binary polar coding (BPC) in that BPC uses a binary-input channel whereas NBPC uses a non-binary input channel. For example, while BPC uses a log likelihood ratio (LLR) with a single value corresponding to a given bit to be shaped, NBPC may use a probability mass function (PMF) to define or represent amplitude shaping target values. As another example, aspects use non-binary transformations, which reduce the number of passes to shape q bits from q passes (for BPC) to 1 pass (for NBPC).

The present disclosure provides a method (100) in a network device. The method (100) includes: transmitting (110) Downlink Control Information, DCI, to a terminal device, the DCI containing information from which a TBS index is derivable. The BS index is usable to determine a TBS from a set of TBSs including TBSs usable with Quadrature Phase Shift Keying, QPSK, and TBSs usable with 16-Quadrature Amplitude Modulation, 16-QAM. When the DCI is for a Narrowband Physical Downlink Shared Channel, NPDSCH, the TBSs usable with 16-QAM are determinable by the terminal device based on a deployment mode.

The invention discloses a high-order QAM (Quadrature Amplitude Modulation) signal demodulation carrier synchronization design method based on secondary loop filtering, which relates to the field of signal processing, gives consideration to steady-state phase difference and capture bandwidth of carrier synchronization, covers various application scenes and provides good demodulation performance. According to the technical scheme, the method comprises the steps that a first loop is designed and mainly comprises a carrier compensator, a digital frequency discriminator, a numerical control oscillator, a first-stage digital loop filter and a frequency locking detector; the two-stage digital loop mainly comprises a carrier compensator, a digital phase discriminator, a numerical control oscillator, a two-stage digital loop filter and a phase locking detector. After the two stages of loops are connected in series, the first-stage loop carries out synchronous compensation on large frequency offset of signals, and the second-stage loop carries out synchronous compensation on small residual frequency offset and phase offset of the signals. The design is monitored through a locking detector, and carrier synchronization of high-order QAM signal demodulation is achieved.

This disclosure provides systems, methods and apparatuses for demodulating multiple-input multiple-output (MIMO) transmissions with N layers with probabilistic shaping according to a distribution such as the Maxwell-Boltzmann distribution. A demodulator at a receiving device projects a received 4N-dimensional point to a 2N-dimensional subspace spanned by probabilistic shaping demod-equivalent receive constellation points to obtain a projected received point. The demodulator performs lattice basis reduction for a 2N-dimensional lattice to obtain a reduced basis lattice. The demodulator obtains a nearest point of the reduced basis lattice to the projected received point using linear demodulation with the reduced basis lattice.

The invention discloses a multivariate channel coding and decoding system based on iterative feedback, and belongs to the technical field of communication. Comprising a transmitting end and a receiving end, wherein the transmitting end comprises a multivariate LDPC (Low Density Parity Check) coding module, a serial-to-parallel conversion / mapping module and a modulator module; and the receiving end comprises a soft demodulator module, a serial-to-parallel conversion / demapping module and a multivariate LDPC soft decoding module. According to the invention, on the basis of multivariate LDPC coding, a special modulation constellation diagram is designed, so that each 16 QAM symbol corresponds to two mutually associated GF4 multivariate LDPC coding code elements, the average Euclidean distance of each code element is maximum, and iterative feedback decoding is introduced, so that the anti-noise performance is improved, and the performance of an optical communication system is improved.