Disclosed is a an apparatus for reducing a reducing a peak to average power ratio (PAPR) for layer division multiplexing (LDM) in an orthogonal frequency division multiplexing (OFDM) system, the apparatus may include a peak remover configured to detect a peak power value of a subcarrier signal that is input and generate a peak removal signal that decreases the detected peak power value, and a processor configured to perform constellation remapping on a first signal generated by combining the subcarrier signal and the peak removal signal and then generate a second signal into which additional data is inserted.

A transmitting apparatus is disclosed. The transmitting apparatus includes an encoder to perform channel encoding with respect to bits and generate a codeword, an interleaver to interleave the codeword, and a modulator to map the interleaved codeword onto a non-uniform constellation according to a modulation scheme, and the constellation may include constellation points defined based on various tables according to the modulation scheme.

A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a negative acknowledgement message indicating a failure to successfully, autonomously recover a compressed transmission including a saturated signal; and transmit a retransmission to enable distortion recovery on the compressed transmission based at least in part on receiving the negative acknowledgement. Numerous other aspects are provided.

Embodiments of the present disclosure relate to a method and system for transmitting a sequence with low peak-to-average-power-ratio (PAPR). A communication system receives control data. A transmitter of the communication system comprises a plurality of sequences which are associated with the control data in the transmitter. The transmitter selects a sequence from the plurality of sequence. The selected sequence is rotated, pre-coded for generating pre-coded sequence. DFT is applied on the pre-coded sequence for generating frequency domain signals. The frequency domain signals are processed and corresponding waveform is transmitted to a receiver of the communication system. The receiver receives the waveform and is processed to extract the sequence from the waveform. The receiver correlates the extracted sequence with plurality of sequences stored in receiver memory to detect the control data. The generated waveform has low PAPR.

A method of signal communication is disclosed comprising providing source data having a predetermined signal power; mapping the source data onto a first modulation scheme to obtain a first set of complex symbols; mapping the source data onto at least one further modulation scheme to obtain at least one further set of complex symbols; combining the first set of complex symbols and the at least one further set of complex signals to form a modulated signal to be forwarded along a communications channel. Beneficially, the predetermined signal power of the source data is split between the first modulation scheme and the at least one further modulation scheme.

A communication system in which multiple shaping codes are selectively and iteratively used to encode a data frame such that possible energy inefficiencies associated with the use of constant-probability codes and/or transmission of dummy constellation symbols can be relatively small. In an example embodiment, the used shaping codes have different respective code rates, and a code selector of the shaping encoder operates to select one of the shaping codes by adaptively matching the rate of the code to the effective rate needed to efficiently encode the unprocessed portion of the data frame. The encoding is carried out in a manner that enables the shaping decoder to unequivocally determine the shaping codes that have been used for encoding each particular data frame based on the same rate-matching criteria as those used by the shaping encoder. At least some embodiments advantageously lend themselves to being implemented using circuits of relatively low complexity.

Aspects of the present application provide methods and devices for using a combined QAM and APSK modulation scheme in a hybrid modulation form in order to benefit from advantages of each respective modulation scheme. The proposed hybrid modulation scheme is less sensitive to phase noise and has lower PAPR than QAM and has very similar performance as QAM with respect to AWGN.

A signal modulation device includes: a conversion module, configured to convert a baseband coded signal and output an in-phase signal sequence and a quadrature signal sequence; a coding expansion module, connected to the conversion module and configured to expand the in-phase signal sequence and the quadrature signal sequence respectively and output an in-phase signal coded sequence and a quadrature signal coded sequence; and a modulation module, connected to the coding expansion module and configured to modulate the in-phase signal coded sequence and the quadrature signal coded sequence and output a radio frequency signal.

A data communication method in which input digital data is received and encoded into an encoded waveform having zero crossings representative of the input digital data. The encoding includes generating the encoded waveform based upon a continuous piecewise function having sinusoidal components. The continuous piecewise function may be used in generating a plurality of symbol waveforms, each of which occupies a period of the encoded waveform and represents bits of the input digital data. The plurality of symbol waveforms are defined so that a value of a phase offset used in the continuous piecewise function is different for each of the plurality of symbol waveforms, thereby resulting in each symbol waveform having a different zero crossing. An encoded analog waveform is generated from a representation of the encoded waveform and transmitted to a receiver.