The multi-channel signal processing device includes a multi-channel continuous waveform (CW) phase shifter module configured to generate phase control and filter interference therein for multiple local oscillator (LO) signals at a same frequency, a multi-channel up-converter module configured to up-convert the multiple LO signals to a desired frequency and filter respective image signals therein, and a multi-channel wideband mixer module configured to receive and mix the up-converted LO signals at the desired frequency from the multi-channel up-converter module with radio frequency (RF) signals.

This document describes techniques for decoding a convolutionally coded signal using a trellis decoder in a drift robust manner. A convolutionally coded and differentially modulated signal may be received. The signal may be decoded using a trellis. A noise prediction loop may be used to reduce noise characteristics of the signal. A frequency offset estimation loop may be used to reduce a frequency offset drift of the signal. The noise prediction loop and the frequency offset estimation loop may be applied at each branch of the trellis.

Circuits for producing signals representative of mean and variance estimations for quadrature amplitude modulation (QAM) are provided where the circuits comprise: sequentially repeated first circuit modules and sequentially repeated second circuit modules configured for producing updates in the corresponding estimation iterations. In one embodiment, a closest negative integer power of 2 is used as a substitute multiplicand when multiplying together two or more outputs of hyperbolic function generating units where the substituted for output is less than one. Size and complexity of the corresponding multiplier can then be reduced.

The present disclosure provides a method implemented in a wireless communication device for estimating a frequency offset between a carrier frequency of a received signal and a frequency of a local oscillator as well as the wireless communication device. The method comprises determining a plurality of phase change candidates for a phase change between a data symbol and a first reference symbol in the signal. The method further comprises generating a collection of constellation symbols from the data symbol and rotating the collection of constellation symbols by the plurality of phase change candidates. Then, one of the phase change candidates corresponding to one of the rotated collections of constellation symbols is selected in such a manner that said one of the rotated collections of constellation symbols matches a set of constellation points best. Next, the frequency offset is determined based on the selected phase change candidate.

This document describes techniques for decoding a convolutionally coded signal using a trellis decoder in a drift robust manner. A convolutionally coded and differentially modulated signal may be received. The signal may be decoded using a trellis. A noise prediction loop may be used to reduce noise characteristics of the signal. A frequency offset estimation loop may be used to reduce a frequency offset drift of the signal. The noise prediction loop and the frequency offset estimation loop may be applied at each branch of the trellis.

Methods, systems, and devices for scrambling for probabilistic constellation schemes (PCSs) in wireless communications are described. In some examples, a first wireless device may scramble a set of amplitude information bits associated with a transport block for transmission to a second wireless device. In such examples, the first wireless device may perform a distribution matching procedure on the scrambled set of amplitude information bits. The first wireless device may encode the set of distributed amplitude bits and, in some cases, may perform a modulation procedure on the encoded set of distributed amplitude bits in accordance with a PCS scheme to obtain a codeword associated with the transport block. In some examples, the first wireless device may transmit the codeword to the second wireless device.

An apparatus of a wireless communication system according to an embodiment is provided. For each frequency component of two or more frequency components, a transmitter of the wireless communication system is configured to transmit, within said frequency component, a transmit signal of said frequency component. A receiver of the wireless communication system is configured to receive, within said frequency component, the transmit signal of said frequency component, which has been transmitted by the transmitter, as a received signal of said frequency component. Each frequency component of the two or more frequency components represents a bandwidth limited signal, which comprises one or more signal portions, and which exhibits a center frequency, wherein the center frequency of each of the two or more frequency components is different from the center frequency of any other one of the two or more frequency components.

Methods and apparatus for wired communications are disclosed. A method for transmitting a data stream through a wired communications channel includes encoding the data stream to produce a first baseband modulating signal I(t) and a second baseband modulating signal Q(t) whose amplitudes together represent a time series of complex symbols (I, Q) each selected from a two-dimensional (2-D) constellation of symbols distributed on the phase plane about the origin such that at least one of the baseband modulating signals has a substantially non-zero mean amplitude, modulating the baseband signals I(t) and Q(t) to produce a modulated signal, wherein the I(t) and Q(t) components of the modulated signals are generally fixed in quadrature, and providing the modulated signal to a wired communications channel.

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and a relevant device, characterized in that the method comprises: generating a cyclic prefix according to a partial time-domain main body signal truncated from a time-domain main body signal; generating a modulation signal based on a portion or the entirety of the partial time-domain main body signal; and generating time-domain symbols based on at least one of the cyclic prefix, the time-domain main body signal and the modulation signal, wherein the preamble symbol contains at least one of the time-domain symbols. Therefore, using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to implement coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels; and generating a modulation signal as a postfix based on the entirety or a portion of the above truncated time-domain main body signal enables the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

Provided are a preamble symbol receiving method and a relevant device, characterized in that: the received preamble symbol contains a time-domain symbol which is generated from a single three-segment structure by a transmitting end according to a predefined generation rule, the single three-segment structure containing: a time-domain main body signal, a prefix generated based on the entirety or a portion of the time-domain main body signal, and a postfix or a hyper prefix generated based on the entirety or a portion of the time-domain main body signal. Therefore, using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to implement coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels; and generating a modulation signal of a postfix or a hyper prefix based on the entirety or a portion of the above truncated time-domain main body signal enables the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.