An RF system using PR-ASK with orthogonal offset is disclosed. In some embodiments, the system includes a PR-ASK signal generator and an orthogonal offset generator. The PR-ASK signal generator can produce a signal representing a sequence of symbols, for example, RFID symbols. The orthogonal offset generator can shift the PR-ASK signal trajectory away from the origin while maintaining the time domain requirements for an RFID signal, such as waveform edge rise and fall times. In some embodiments stored waveforms incorporating the controlled orthogonal offset are used to synthesize a sequence of symbols. The stored waveforms may also include nonlinear and/or linear predistortion to reduce computational complexity. The waveforms can be represented in Cartesian coordinates for use in a direct conversion transmitter or polar coordinates for use in a polar modulation transmitter. An RFID system can also include a receiver to receive incoming RFID signals.

Probabilistic constellation shaping (PCS) is applied to a desired probability distribution over the 2-D constellation points. Constellation points are partitioned into multiple disjoint sets in which all the constellation points within a subset have the same energy level (i.e., amplitude) or distance from the origin on the complex plane. Each of the sets may be further subdivided into smaller disjoint sets of constellation points to facilitate labeling of the constellation points. The sets may be indexed from 0 to the total number of disjoint sets to form an index set. The desired distribution may then be applied over the index set either using a distribution matcher (DM) or using a lookup table. The desired distribution may be generated before forward error correction (FEC) encoding that preserves the generated amplitude distribution through FEC encoding of data bits. The scheme may map the FEC encoded data bits to the constellation points, such that the probability of occurrence of each signal set (with a specific energy level) follows the desired probability distribution within a fixed codeword length. In addition, PCS can be applied to both square and non-square constellations, which may or may not be arranged on a Cartesian grid.

A polar transmitter provided for transmitting a phase/frequency modulated and amplitude modulated transmit signal and a method for generating a transmit signal using a polar transmitter are described. An example polar transmitter comprises a phase locked loop for generating a phase/frequency modulated precursor of the transmit signal. The phase locked loop comprises at its input a phase error detection unit for detecting a phase error of the precursor fed back from the output of the phase locked loop to the phase error detection unit as a feedback signal. The polar transmitter comprises a digital amplitude modulator for amplitude modulation of the precursor, resulting in the transmit signal. The digital amplitude modulator is arranged within the phase locked loop for amplitude modulation of the precursor before being output by the PLL. The phase error detection unit is further provided for detecting the amplitude of the feedback signal.

The disclosure relates to an IQ mismatch correction module for a radio receiver, the IQ mismatch correction module comprising: an input terminal configured to receive an input signal; an output terminal configured to provide a filtered output signal; a mismatch detection module comprising: one or more bandpass filters configured to receive, from the input terminal or output terminal, a bandpass input signal and to pass a plurality of sub-bands of the bandpass input signal to provide respective bandpass filtered signals; one or more amplitude and phase mismatch detectors configured to determine amplitude and phase mismatch coefficients based on the bandpass filtered signals from the plurality of sub-bands; a transformation unit configured to apply a transformation to the amplitude and phase mismatch coefficients to provide correction filter coefficients for the plurality of sub-bands; and a filter module configured to: receive the filter coefficients for the plurality of sub-bands from the mismatch detection module; and filter the input signal in accordance with the received filter coefficients to provide the filtered output signal.

An EVM measurement value is appropriately determined while CPE/ICI correction is taken into account. In a measurement apparatus (300), an EVM measurer (305) measures a modulation quality of a signal transmitted from a transmission apparatus. An EVM determiner (306) determines whether or not the measurement value of the modulation quality is equal to or less than a first requirement value, in a case where correction relating to a phase noise of the transmission apparatus is necessary in a reception apparatus. The first requirement value herein is higher than a second requirement value used in the determination of the measurement value in a case where the correction relating to the phase noise of the transmission apparatus is unnecessary in the reception apparatus.

Provided is a wireless communication apparatus wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. In the wireless communication apparatus, an encoding section encodes and outputs transmitting data to a bit converting section, and the bit converting section converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’ and outputs it to a modulating section. The modulating section modulates the bit string inputted from the bit converting section by using a single modulation mapper and a plurality of data symbols are generated.

Provided is a wireless communication apparatus wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. In the wireless communication apparatus, an encoding section encodes and outputs transmitting data to a bit converting section, and the bit converting section converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’ and outputs it to a modulating section. The modulating section modulates the bit string inputted from the bit converting section by using a single modulation mapper and a plurality of data symbols are generated.

Methods and apparatuses for transmitting or receiving data for NBIoT supporting 16QAM modulation are disclosed. A method comprises receiving a control signal, wherein the control signal includes a MCS index and a resource assignment index; and receiving a control signal, wherein the control signal includes a MCS index and a resource assignment index, wherein the transport block size is determined by a combination of a transport block size index and the resource assignment index, and the transport block size index is determined by at least one of the MCS index and the resource assignment index.

Methods and apparatuses for transmitting or receiving data for NBIoT supporting 16QAM modulation are disclosed. A method comprises receiving a control signal, wherein the control signal includes a MCS index and a resource assignment index; and receiving a control signal, wherein the control signal includes a MCS index and a resource assignment index, wherein the transport block size is determined by a combination of a transport block size index and the resource assignment index, and the transport block size index is determined by at least one of the MCS index and the resource assignment index.

A coding and modulation apparatus and method are presented. The apparatus (10) comprises an encoder (11) that encodes input data into cell words, and a modulator (12) that modulates said cell words into constellation values of a non-uniform constellation. The modulator (12) is configured to use, based on the total number M of constellation points of the constellation, the signal-to-noise ratio SNR in dB and the channel characteristics, a non-uniform constellation from a group of constellations comprising one or more of predetermined constellations defined by the constellation position vector u1 . . . v, wherein v=sqrt(M)/2−1.