A Belief Propagation (BP) equalization method and apparatus, a communication device and a storage medium are disclosed. The method may include: splitting a received signal Y.sub.c, a channel estimation H.sub.c and a symbol estimation X.sub.c into real parts and imaginary parts to obtain a received signal matrix Y, a channel estimation matrix H and a symbol estimation matrix X (S101); performing orthogonal triangular (QR) decomposition on the channel estimation matrix H to obtain an equivalent received signal Y.sub.bp, an equivalent channel R and a noise power σ.sup.2 (S102); and performing iteration based on the equivalent received signal Y.sub.bp, the equivalent channel R and the noise power σ.sup.2 to obtain a position probability of per stream symbol (S103).

The embodiments herein relate to a method in a first network node (301) for handling Automatic Gain Control, AGC, scaling and Transmit Power Control, TPC, scaling of a signal received from a second network node (305). The first network node AGC compensates the signal for any AGC scaling changes. The AGC compensating the signal results in an AGC compensated signal comprising a constant AGC scaling. The first network node detects a TPC scaling change of the signal. The detection is based on the signal after the TPC scaling change and based on a predicted channel estimate. The predicted channel estimate is based on the signal before the TPC scaling change. The first network node TPC compensates for the detected TPC scaling change. The TPC compensation results in an AGC and TPC compensated signal comprising the constant AGC scaling and a constant TPC scaling according to the detected TPC scaling change.

The disclosure provides for interference mitigation for wireless signals in unlicensed spectrum. A wireless device may receive a combined signal including a first radio access technology (RAT) signal and a second RAT signal. The wireless device may generate, using a first RAT receiver in a first processing path, a channel estimate for the first RAT signal based on a previously decoded signal of the first RAT. The wireless device may reduce interference to the second RAT signal caused by the first RAT signal, in a second processing path, using the channel estimate. The wireless device may further decode the second RAT signal. The wireless device may remodulate the decoded signal using a transmitter to generate a remodulated second RAT signal. The remodulated second RAT signal may be canceled from the combined signal. The wireless device may decode a remaining portion of the combined signal including the first RAT signal.

Channel estimation with reduced overhead in a filter bank multi-carrier (FBMC) system is enabled by use of frequency-time blocks each comprising a pilot field with two pilot symbols and data symbols outside the pilot field. In embodiments, nearest neighbors of the pilot field are populated with data symbols which fulfill one or more symmetry relations enabling approximate interference cancellation. In a first embodiment, the pilot field consists of two frequency-consecutive and time-coinciding positions; the pilot field may be time-initial in a transmission or may be located in the interior of the transmission. In a second embodiment, a block comprises two frequency-coinciding and time-consecutive pilot symbols; the pilot field may be frequency-initial in a transmission or may be located in the interior of the transmission.

A method of receiving a signal by a receiver in a mobile communication system is provided. The method includes: receiving a reference signal from a transmitter; determining first channel information based on the received reference signal; receiving a data signal based on the first channel information; and determining second channel information based on the received data signal and the first channel information. Iterative channel estimation is performed to reduce channel estimation errors by determining errors of signals received from a turbo decoding unit and using symbol information as pilots even in subcarriers where the pilot signals are not transmitted, and to increase the accuracy of LLR calculation through an iteration process such as a detection and decoding process in comparison with the conventional technology, thereby increasing the reception performance of the turbo decoding unit and improving communication efficiency.

Disclosed is a method for receiving control information, one embodiment of the present invention, in which a terminal receives control information by means of an enhanced physical downlink control channel (EPDCCH) in a wireless communication system, comprising the steps of: estimating a channel in subframe N, and blind-decoding on the basis of the result of the channel estimation; and blind-decoding in subframe N+L (L>=1), wherein, if subframe N and subframe N+L are included in a single subframe bundling group (SBG), then the reference signal associated with the channel estimation in subframe N is also used for the channel estimation for blind-decoding in subframe N+L.

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.

Methods, systems, and devices for wireless communication are described. A wireless communications system may support techniques for using non-staggered reference signals to increase the efficiency of the system and reduce the complexity of channel estimation. A base station may schedule a transmission to a user equipment (UE) including pilot tones mapped to a first symbol and a second symbol. In some cases, the pilot tones on the first and second symbols may be non-contiguous, and the base station may scramble the pilot tones on the first and second symbols according to the same scrambling sequence. In other cases, the pilot tones on the first and second symbols may be contiguous, and the pilot tones may be scrambled according to the same or different scrambling sequences. These techniques may result in reduced complexity for interference estimation and channel estimation at a UE.

In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive and convert a plurality of orthogonal frequency division multiplexing (OFDM) samples into a plurality of frequency carriers; a detector coupled to the FFT engine to determine a channel estimate for a first frequency carrier using a first channel estimate for the first frequency carrier and a plurality of other channel estimates, each of the plurality of other channel estimates for one of a plurality of neighboring frequency carriers within an evaluation window, and determine a log likelihood ratio (LLR) for the first frequency carrier using the channel estimate for the first frequency carrier; and a decoder coupled to the detector to decode a first OFDM symbol comprising the first frequency carrier using the LLR for the first frequency carrier.

In a transmitter apparatus, a known reference signal is superimposed on top of a data signal that is typically not known a priori to a receiver and the combined signal is transmitted. At a receiver, an iterative channel estimation and equalization technique is used to recover the reference signal and the unknown data signal. In the initial iteration, the known reference signal is recovered by treating the data signal as noise. Subsequent iterations are used to improve estimation of received reference signal and the unknown data signal.