A radio frequency (RF) rake receiver may include a plurality of diversity receive paths, with each diversity receive path including a respective rake receiver despreader, and a tracking loop. The tracking loop may be configured to generate a composite timing signal based upon the rake receiver despreaders, and provide the composite timing signal to the diversity receive paths.

Methods, systems, and devices for the design of symbol-group based spreading schemes are described. An exemplary method for wireless communication includes transmitting, by a terminal, a first spread signal that is generated by spreading a first group of N data symbols using a first set of N sequences, where N is a symbol-group length, L is a spreading length, each of the first set of N sequences is from an orthogonal spreading sequence set that comprises L sequences, and each of the L sequences is of length L. Another exemplary method for wireless communication includes transmitting, by a network node, an indication of a first set of N sequences, and receiving a first spread signal comprising a group of N data symbols spread using the first set of N sequences.

A method of generating a BOC correlation function based on partial correlation functions, an apparatus for tracking a BOC signal, and a spread spectrum signal receiver system using the same are disclosed herein. The apparatus includes a frequency offset compensation unit, a local code generation unit, a mixer, a delay lock loop (DLL), a phase lock loop (PLL), and a data extraction unit. The frequency offset compensation unit outputs a compensated received signal with respect to a received signal. The local code generation unit generates a delay-compensated local code based on a code delay value. The mixer mixes the delay-compensated local code with the frequency offset-compensated received signal. The DLL repeatedly tracks and calculates a code delay value. The PLL repeatedly calculates a carrier frequency compensation value. The data extraction unit extracts spreading data from a mixture of the delay-compensated local code and the compensated received signal.

Methods, systems, and devices for the design of symbol-group based spreading schemes are described. An exemplary method for wireless communication includes transmitting, by a terminal, a first spread signal that is generated by spreading a first group of N data symbols using a first set of N sequences, where N is a symbol-group length, L is a spreading length, each of the first set of N sequences is from an orthogonal spreading sequence set that comprises L sequences, and each of the L sequences is of length L. Another exemplary method for wireless communication includes transmitting, by a network node, an indication of a first set of N sequences, and receiving a first spread signal comprising a group of N data symbols spread using the first set of N sequences.

A baseband tracking channel in a GNSS receiver is provided. The baseband tracking channel comprises: a code generator to generate a local signal correlating with an incoming signal received by the GNSS receiver; a multiplier that multiplies the local signal with a baseband signal corresponding to an incoming signal received by the GNSS receiver to generate a code removed signal; a prompt correlator including at least one integration register that integrates samples of the code removed signal corresponding to a first portion of each pseudorandom noise code chip of the code removed signal to provide a first integration register output, and integrates samples corresponding to a second portion of each PRN code chip to provide a second integration register output; and a side peak tracking detection module that generates information indicating when side peak tracking is occurring based on the first integration register output and the second integration register output.

A spread-spectrum-signal reception apparatus includes a controller to obtain a phase comparison value that is a phase of a spread code at a time at which initialization of a phase of the spread code is performed and which corresponds to a timing of a top of a frame of a received signal, and to output an initialization instruction including the phase comparison value when having determined that a current time is within a range of a time window; and a signal processor to demodulate the received signal in accordance with the spread code, to perform a frame synchronizing process on the demodulated signal to detect a frame timing, and to perform the initialization at a timing determined in accordance with a result of comparison between the phase comparison value included in the initialization instruction and a phase of the spread code at the frame timing.

Noise distribution shaping for signals, particularly for the application in receivers for CDMA signals. An embodiment provides a method for noise distribution shaping for signals comprising the acts of generating a blanking control signal by comparing a received signal comprising transitions with at least one blanking threshold, determining transitions of the received signal and zones around the determined transitions, and generating a transitions control signal comprising the determined transitions and zones, adapting the at least one blanking threshold or the received signal according to an offset value depending on the amplitude of the received signal and on the transitions control signal, and modifying the noise distribution of the received signal by applying blanking of the received signal under control of the blanking control signal.

Disclosed is a method for recovering an original signal in a DS-CDMA system based on complexity reduction. In such a method, first, a partial derivative for rMLL is calculated by using a partial derivative generated by applying fast Fourier transform (FFT) to a reduced negative marginal log likelihood (rMLL) obtained by applying a law of log determinant to a Gaussian process regression (GPR) scheme used for the multi-user detection and thereafter, integrating stochastic gradient descent (SGD). Thereafter, the rMLL is calculated by using the partial derivative for the rMLL and a hyper-parameter is updated to a convergence point until an error gap is converged by repeated calculation of the rMLL. Next, a kernel function used for estimating a matched filter is calculated by using the hyper-parameter estimated through the convergence and the original signal for each of multi-users is recovered by using the kernel function.

Disclosed is a method for recovering an original signal in a DS-CDMA system based on complexity reduction. In such a method, first, a partial derivative for rMLL is calculated by using a partial derivative generated by applying fast Fourier transform (FFT) to a reduced negative marginal log likelihood (rMLL) obtained by applying a law of log determinant to a Gaussian process regression (GPR) scheme used for the multi-user detection and thereafter, integrating stochastic gradient descent (SGD). Thereafter, the rMLL is calculated by using the partial derivative for the rMLL and a hyper-parameter is updated to a convergence point until an error gap is converged by repeated calculation of the rMLL. Next, a kernel function used for estimating a matched filter is calculated by using the hyper-parameter estimated through the convergence and the original signal for each of multi-users is recovered by using the kernel function.

A spread-spectrum-signal reception apparatus includes a controller to obtain a phase comparison value that is a phase of a spread code at a time at which initialization of a phase of the spread code is performed and which corresponds to a timing of a top of a frame of a received signal, and to output an initialization instruction including the phase comparison value when having determined that a current time is within a range of a time window; and a signal processor to demodulate the received signal in accordance with the spread code, to perform a frame synchronizing process on the demodulated signal to detect a frame timing, and to perform the initialization at a timing determined in accordance with a result of comparison between the phase comparison value included in the initialization instruction and a phase of the spread code at the frame timing.