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 (i1).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.

A method of wireless communication includes transmitting frames from a transponder to a reader and synchronizing between a reader carrier frequency and an active load modulation (ALM) carrier frequency within each transmitted frame. Each transmitted frame includes ALM carrier bursts generated from subcarrier modulation by binary phase shift keying (BPSK) data encoding and producing signal oscillations at a transponder antenna after each ALM carrier burst generation, The synchronizing occurs at each phase change of the data encoding when no burst is generated during a half period of the subcarrier preceding the phase change and a half period of the subcarrier following this phase change. The transponder antenna has a moderate quality factor sufficient to naturally damp the signal oscillations so that the synchronizing is performed without performing any controlled signal oscillations damping.

Examples herein disclose apparatus and systems for hybrid vector based polar modulator schemes that may use a series of polar modulators to create a system of vector modulators. The resulting polar response may be de-composed into the sum of the polar modulators. This approach allows accurate phase modulation in two such links without the need for high resolution AM part to cover the IQ plane of a QAM modulator.

A transmitter, a receiver, and a signal processing method are provided. The transmitter includes a constellation mapper, a signal conversion module, a digital signal processor, and a digital-to-analog converter. The constellation mapper is configured to determine a mapping relationship between a bit stream and a constellation point in a polar coordinate system, and generate a constellation symbol data flow according to the mapping relationship. The signal conversion module is configured to convert the constellation symbol data flow into an amplitude signal and a phase signal, where the amplitude signal is a 2-level analog signal, and the phase signal is an 8-level digital signal. The digital signal processor is configured to perform digital signal processing on the phase signal, to generate a multi-level digital signal. The digital-to-analog converter is configured to convert the multi-level digital signal into a multi-level analog signal.

Systems and methods for up-sampling a polar amplitude sample stream in a polar modulator are disclosed. In some embodiments, a process includes receiving, at a polar modulator, an in-phase sample stream and a quadrature sample stream which together characterize a data signal in an IQ plane. The process includes generating a polar amplitude sample stream and a polar phase sample stream. The process includes generating an up-sampled polar amplitude sample stream by (i) identifying an origin crossing of the data signal in the IQ plane, (ii) responsively adjusting an inversion trigger, (iii) selectively applying an inversion to the polar amplitude sample stream based on the inversion trigger, (iv) interpolating the selectively inverted polar amplitude sample stream, and (v) removing the inversion from the interpolated selectively inverted polar amplitude sample stream. The process includes modulating a carrier signal using the up-sampled polar amplitude stream and the polar phase sample stream.

A method (C) for converting a data signal (U), comprising (i) providing an input symbol stream (B) representative of the data signal (U), (ii) demultiplexing (DMX) the input symbol stream (B) to consecutively decompose the input symbol stream (B) into a number m of decomposed partial symbol streams (B_1, . . . , B_m), (iii) applying on each of the decomposed partial symbol streams (B_1, . . . , B_m) an assigned distribution matching process (DM_1, . . . , DM_m), thereby generating and outputting for each decomposed partial symbol stream (B_1, . . . , B_m) a respective pre-sequence (bn_1, . . . , bn_m) or n_j symbols as an intermediate output symbol sequence, and (iv) supplying the pre-sequences (bn_1, . . . , bn_m) to at least one symbol mapping process (BM) to generate and output a signal representative for a final output symbol sequence (S) as a converted data signal. Each of the distribution matching processes (DM_1, . . . , DM_m) and the symbol mapping process (BM) are based on a respective assigned alphabet (ADM_1, . . . , ADM_m; ABM) of symbols and the cardinality of each of the alphabets (ADM_1, . . . , ADM_m) of the distribution matching processes (DM_1, . . . , DM_m) is lower than the cardinality of the alphabet (ABM) of the symbol mapping process (BM).

Certain aspects of the present disclosure generally relate to wireless communication. More particularly, aspects of the present disclosure provide multiplexing schemes which may be suited for the single carrier waveform. For example, some techniques and apparatuses described herein permit multiplexing of multiple, different data streams without destroying the single-carrier properties of the waveform. Additionally, or alternatively, some techniques and apparatuses described herein may provide unequal error protection, unequal bandwidth allocation, and/or the like as part of the multiplexing schemes. Examples of multiplexing schemes described herein include in-phase/quadrature (I/Q) multiplexing, superposition quadrature amplitude modulation (QAM) based at least in part on layered bit mapping, polarization division multiplexing of QAM with superposition coding, and frequency division multiplexing using UE-specific beams.

Embodiments relate to a transceiver configured to send a send signal to a radio module having a backscatter modulator or a load modulator, the send signal including two different signal portions based on mutually independent signals or signal sources.

A polar transmitter includes an amplitude path comprising an amplitude signal that corresponds to an amplitude of a vector sum of an in-phase input signal and a quadrature input signal; a phase path comprising a phase modulator configured to phase-modulate a phase signal that corresponds to the phase of the vector sum of the in-phase input signal and the quadrature input signal; a digital power amplifier (DPA) configured to amplify the phase-modulated (PM) input signal based on the amplitude signal; a tunable matching network coupled to an output of the DPA and configured to adjust a load impedance of the DPA; and a controller configured to adjust the matching network based on a look-up table with respect to amplitude and frequency information, where the look-up table indicates a plurality of optimal operation modes of the matching network for specific combinations of amplitude and frequency information.

A communication system transmits an input block of bits over a communication channel using a prefix tree that maps a dyadic distribution of compositions of output symbols to prefixes of variable lengths. A path to each leaf of the prefix tree is defined by a prefix formed by a unique sequence of binary values of a length equal to a depth of the leaf. Each leaf is associated with a composition that has at least a number of unique permutations equals to two in a power of a length of a suffix of the block of input bits. The system selects a composition identified in the prefix tree by a prefix in the input block of bits, permutes the selected composition according to a suffix in the input block of bits, and transmits the permuted composition over a communication channel.