Receiver and method in a receiver, for receiving a signal from a transmitter in a wireless communication system, based on OFDM. The method comprises: receiving a plurality of signals y from the transmitter; determining a group T of REs for which the CEE is assumed to be constant; extracting the determined group T of REs, from the received signals y; computing noise and CEE covariance matrix R.sub.ww for the extracted T REs, initialised as: R.sub.ww=(N.sub.0+Mσ.sup.2)I; computing a MMSE filter W.sup.MMSE, based on the computed noise and CEE covariance matrix R.sub.ww; and obtaining an MMSE estimate {circumflex over (x)} of payload data x comprised in the received signals y, associated with the extracted T REs by applying the computed filter W.sup.MMSE to the extracted T REs of the received signals: {circumflex over (x)}=W.sup.MMSEy.

A receiving device comprises a signal detection unit, a reliability unit coupled to the signal detection unit and a decoding unit coupled to the signal detection unit and the reliability unit. The signal detection unit is for receiving a plurality of compensated symbols on a plurality of subcarriers, to generate a plurality of soft information and a plurality demodulated symbols of the plurality of compensated symbols according to the plurality of compensated symbols. The reliability unit is for generating a plurality of weights of the plurality of soft information according to a plurality of reliability information of the plurality of subcarriers. The decoding unit is for decoding the plurality of demodulated symbols according to the plurality of soft information and the plurality of weights, to generate a plurality of decoded bits.

An apparatus and a method. The apparatus includes a channel estimation (CE) module, including a first input for receiving pilot resource element (RE) observations, a second input for receiving data RE observations, a third input for receiving log-likelihood ratios (LLRs), and an output; a detector, including a first input connected to the output of the CE module, a second input for receiving data RE observations, and an output connected to the third input of the CE module; and a decoder, including an input connected to the third input of the CE module, and an output.

The presently claimed invention relates generally to a method and an apparatus for pilot decontamination for massive MIMO system and, more particularly, to a massive MIMO communication system based on channel estimation with topological interference alignment.

A user equipment device operating in a cellular communications system includes a neighbor cell searcher configured to receive a first reference signal transmitted from a base station of a first cell of the cellular communications system and determine first channel information associated with the first cell, and receive a second reference signal transmitted from a base station of a second cell of the cellular communications system and determine second channel information associated with the second cell. A channel estimator is configured to generate correlations between times and frequencies associated with reception of the first reference signal and the second reference signal, and generate a channel estimate corresponding to the first reference signal based on the first channel information, the second channel information, and the correlations.

Systems and methods for detecting potentially active user equipment (UE) in a network are provided. A set of potentially active UEs is detected using an iterative method. In a first iteration UE detection is performed using compressed sensing (CS) based on first pilot sequences to detect a first set of potentially active UEs. Channel estimation is then performed for the first set of potentially active UEs. In subsequent iterations, UE detection is performed using CS to detect another set, typically reduced in size, of potentially active UEs using results of the channel estimation from the previous iteration. Channel estimation is then again performed for the new set of potentially active UEs. After the last iteration, the set of potentially active UEs detected in the last iteration is output as the determined set of potentially active UEs along with channel estimates for the set of potentially active UEs determined in last iteration.

The present invention discloses a pilot frequency position determining method based on pilot frequency interval optimization and a transceiver device. The method optimizes a pilot frequency position on the basis of better use of pilot frequency in a wireless system for sampling frequency synchronization and residual phase tracking. After an optimal pilot frequency position is obtained according to the method, a transmitting terminal inserts a pilot frequency sequence at a corresponding pilot frequency position, a receiving terminal learns the pilot frequency position and the pilot frequency sequence, and after channel equalization, deviation is tracked by means of coherent detection of a local sequence. For the aforementioned method, the present invention further provides a transceiver device of a related pilot frequency module in the wireless system. The pilot frequency position can be better determined without increasing system complexity, and the present invention significantly improves the system performance.

Noise and interference may be estimated at a user equipment (UE) in a system that may support transmissions having different transmission time intervals (TTIs). The UE may perform a channel estimation for a first set of transmissions having a first TTI based at least in part on an estimated interference from a second set of transmissions having a second TTI that is shorter than the first TTI. The UE may perform channel estimation for orthogonal frequency division multiplexing (OFDM) symbols of the first set of transmissions. The first set of transmissions may then be demodulated based at least in part on the channel estimation for the first set of transmissions. Noise and interference may also be estimated based on one or more null tones within one or more OFDM symbols of the allocated resources.

There are provided systems, methods, and interfaces for optimization of the fronthaul interface bandwidth for Radio Access Networks and Cloud Radio Access Networks.

Bayesian Inference based communication receiver employs Markov-Chain Monte-Carlo (MCMC) sampling for performing several of the main receiver functionalities. The channel estimator estimates the multipath channel coefficients corresponding to a signal received with fading. The symbol demodulator demodulates the received signal according to a QAM constellation, so as to generate a demodulated signal, and estimate the transmitted symbols. The decoder reliably decodes the demodulated signals to generate an output bit sequence, factoring in redundancy induced at a certain code rate. A universal sampler may be configured to use MCMC sampling for generating estimates of channel coefficients, transmitted symbols or decoder bits, for aforementioned functionalities, respectively. The samples may then be used in one or more of the receiver tasks: channel estimation, signal demodulation, and decoding, which leads to a more scalable, reusable, power/area efficient receiver.