A communication method, a communications apparatus, and a storage medium are disclosed, to reduce a probability that consecutive bit errors occur in a communications system. A received to-be-sent signal is modulated to obtain a modulated signal, and N rounds of operations are further performed on the modulated signal to obtain an encoded signal. An output of the 1.sup.st-round operation in the N rounds of operations is determined based on the modulated signal and an output that is of the N.sup.th-round operation and that is processed by a first delay circuit, and an output of the i.sup.th-round operation in the N rounds of operations is determined based on an output of the (i−1).sup.th-round operation and an output that is of the N.sup.th-round operation and that is processed by a second delay circuit, where i is an integer greater than 1 and less than or equal to N.

Embodiments of this disclosure provide a signal transmission apparatus, a carrier phase recovery apparatus and method. By inserting phase modulation signals with variable amplitudes into data modulation signals and performing carrier phase recovery on received signals at a receiving end according to the phase modulation signals, the apparatuses and methods are applicable to communications systems of various modulation formats and are compatible with existing communications systems, and calculation complexity is relatively low. Furthermore, as the amplitudes of the inserted phase modulation signals are variable, the phase modulation signals may be flexibly configured in data modulation signals, to lower redundancy and influence on the system capacity is relatively small.

The present invention discloses data receiving and sending methods and apparatuses and a system, and relates to the field of communications technologies. The data receiving method includes: receiving a data carrier; deciding polar radius values of multiple labeled constellation points carried at a pre-determined location in the data carrier, to determine a numerical value indicated by a polar radius value of each labeled constellation point in the multiple labeled constellation points; determining, according to a sequence including numerical values indicated by polar radius values of all the labeled constellation points in the multiple labeled constellation points, a demodulation scheme of a constellation point, other than the multiple labeled constellation points, carried in the data carrier; and demodulating, according to the determined demodulation scheme, the constellation point, other than the multiple labeled constellation points, carried in the data carrier.

This application relates to the field of wireless communications technologies, and in particular, to a data processing method, apparatus, and system. This application provides a data processing method. A data sending device modulates a to-be-transmitted bit sequence, splits a real part and an imaginary part of a complex-valued symbol that is obtained through the modulation into two symbols to form a symbol sequence, performs phase rotation of symbols in the symbol sequence, and performs sending by using a single carrier frequency division multiple access (SC-FDMA) symbol. This application is intended to reduce a peak-to-average power ratio (PAPR) of a transmit signal of an orthogonal frequency division multiplexing (OFDM) system by splitting a real part and an imaginary part of a to-be-transmitted signal, and improve link quality of an entire transmission system.

Methods and systems for I/O mismatch calibration and compensation for wideband communication receivers may include receiving a radio frequency (RF) signal in a receiver of a communication device, down-sampling said received RF signal to generate a channel k and its image channel −k at baseband frequencies, determining average in-phase (I) and quadrature (Q) gain and phase mismatch of said channel k and said image channel −k, removing said average I and Q gain and phase mismatch of said channel k and said image channel −k, determining, after said removing said average I and Q gain and phase mismatch, a residual phase tilt of said channel k and said image channel −k, and compensating for said determined residual phase tilt of said channel k and said image channel −k utilizing a phase tilt correction filter.

An outphasing amplifier having: a first branch to receive and process a first branch signal, the first branch signal being phase modulated, with constant amplitude envelope; and a second branch arranged to receive and process a second branch signal, the second branch signal being phase modulated, with constant amplitude envelope, and at least a portion of the second branch signal anti-phase from the first branch signal, wherein each branch includes: circuitry arranged to process the signal to reduce the energy in sidebands of the signal away from the central frequency, while retaining the phase information in the signal; and an amplifier arranged to amplify the filtered and re-asserted branch signal.

A digital quadrature modulator holds local oscillator circuitry configured to provide local oscillator signals, and local oscillator polarity logic circuitry configured to select an In-phase and a Quadrature local oscillator signal according to a sign bit of an In-phase control word and a sign bit of a Quadrature control word, respectively. The modulator holds a number of local oscillator control logic circuits, each configured to generate a conditioned signal by gating one or both of the selected local oscillator signals according to values of the In-phase control word and/or values of the Quadrature control word. The modulator has one or more sets of switched-capacitor units, where each unit has an output provided by an output capacitor, and where a signal at the input side of the output capacitor is controlled by a conditioned signal. The outputs of at least two of the switched-capacitor units are combined in a common node.

A carrier-phase recovery method includes: (i) applying a first carrier-phase recovery algorithm to complex-valued symbols of a signal received by a product detector, yielding coarse phase-estimates, the signal being modulated per an M-QAM scheme; (ii) modelling the coarse phase-estimates as a weighted sum of M probability-density functions of an M-component mixture model; (iii) optimizing the M probability-density functions with an expectation-maximization algorithm to yield M optimized probability-density functions; (iv) mapping, based on the M optimized probability-density functions, the coarse phase-estimates to one of M symbols corresponding to the QAM scheme, each coarse phase-estimate mapped to a same symbol belonging to a same one of M clusters; (v) applying a second carrier-phase recovery algorithm to each of the M clusters to generate refined phase-estimates each corresponding to a respective coarse phase-estimate; and (vi) mapping, based on the M optimized probability-density functions, each refined phase-estimate to one of the M symbols.

Methods, systems, and devices for wireless communications are described for optimizing index modulated (IM) communications between a user equipment (UE) and a base station. The UE may identify a quantity of subcarriers for IM communications and transmit a message including an indication of the quantity of subcarriers to the base station. In some examples, the UE may transmit an indication of one or more subcarriers to exclude from IM communications. The base station may receive the indication of the quantity of subcarriers and/or the indication of the blacklisted subcarrier(s) and may determine a number of active subcarriers to be used based on at least the indication of the quantity of subcarriers. The base station may transmit an indication of the number of active subcarriers to the UE. The UE may process one or more received IM downlink signals based on the quantity of subcarriers.

A digital modulator according to the present disclosure includes a polar converter that generates a phase signal and an amplitude signal from a baseband signal, an RF phase signal generator that generates an RF phase signal on the basis of the phase signal, a rectangulating unit that generates a rectangular RF phase signal by converting the RF phase signal into a rectangular shape, a time interleaver that time interleaves the amplitude signal and outputs first and second time interleaved signals, a ΔΣ modulator that ΔΣ modulates the first and second time interleaved signals on the basis of the rectangular RF phase signal and outputs first and second ΔΣ modulated signals, and a selector that selects and outputs one of the first and second ΔΣ modulated signals on the basis of the rectangular RF phase signal.