A signal detection method for a MIMO-OFDM wireless communication system includes obtaining a channel matrix of each subcarrier for each MIMO-OFDM data packet; receiving a reception vector of each subcarrier; performing MIMO detection for a first OFDM symbol and channel matrix preprocessing to generate a global dynamic K-value table; performing MIMO detection for each subsequent OFDM symbol, the MIMO detection includes: performing the following steps for each subcarrier of a current OFDM symbol: transforming the reception vector of the current subcarrier into a LR search domain; and obtaining a LR domain candidate transmission vector of the current subcarrier, a K-value applied to each search layer of the current subcarrier during the K-best search is a global dynamic K-value in the global dynamic K-value table corresponding to the search layer.

A receiver detects a received signal, transmitted by a transmitter to carry payload data as Orthogonal Frequency Division Multiplexed (OFDM) symbols in divided frames, each frame including a preamble including plural bootstrap OFDM symbols. A detector circuit detects, from the bootstrap OFDM symbols, a synchronization timing for converting a useful part of the bootstrap OFDM symbols into the frequency domain. A bootstrap processor detects an estimate of the channel transfer function from a first OFDM symbol, and a demodulator circuit recovers the signaling data from the bootstrap OFDM symbols using the estimate. The bootstrap processor includes an up-sampler configured to receive the bootstrap OFDM symbols, to form an up-sampled frequency domain version of the bootstrap OFDM symbol, and an output processor configured to identify a peak correlation result, to determine frequency offset of the received signal from a relative position of the peak correlation result in the frequency domain.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a primary digital predistortion (DPD) layer and a secondary DPD layer. The primary DPD layer includes a DPD coefficient estimation module configured to update primary signal generation coefficients based on comparing a secondary predistorted signal (U.sub.out) with a detected feedback signal (Y.sub.out), and a primary distortion compensation processing module configured to generate a primary predistorted signal (U.sub.out′) based on the secondary predistorted signal (U.sub.out) using the updated primary signal generation coefficients. The secondary DPD layer includes a signal characteristic estimation module configured to update secondary signal generation coefficients based on comparing an input signal (S.sub.in) with the detected feedback signal (Y.sub.out), and a secondary distortion compensation processing module configured to generate the secondary predistorted signal (U.sub.out) based on the input signal (S.sub.in) using the updated secondary signal generation coefficients.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes an intermodulation distortion (IMD) filter module configured to filter a detected feedback signal (Y.sub.in) to generate a targeted filtered signal (Y.sub.out), a digital pre-distortion (DPD) coefficient estimation module configured to update signal generation coefficients based on comparing an input signal (S.sub.in) with the targeted filtered signal (Y.sub.out), and a distortion compensation processing module configured to generate a pre-distorted signal (U.sub.out) based on the input signal (S.sub.in) using the updated signal generation coefficients.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a signal decomposition module configured to extract a low-frequency signal (S.sub.lo) and a high-frequency signal (S.sub.hi) from an input signal (S.sub.in); a distortion compensation processing module configured to generate a pre-distorted low-frequency signal (U.sub.lo) and a pre-distorted high-frequency signal (U.sub.hi) based on the received low-frequency and high-frequency signals using signal generation coefficients; a signal combining module configured to combine the pre-distorted low-frequency signal (U.sub.lo) and the pre-distorted high-frequency signal (U.sub.hi); and a signal characteristic estimation processing module configured to update the signal generation coefficients used by the distortion compensation processing module based on comparing the low-frequency signal (S.sub.lo) and the high-frequency signal (S.sub.hi) with a detected feedback low-frequency signal (Y.sub.lo) and a detected feedback high-frequency signal (Y.sub.hi).

The present invention discloses an ML (Maximum Likelihood) detector comprising: a search value selecting circuit selecting a first-layer search value; and an ML detecting circuit. The ML detecting circuit executes the following steps: selecting K first-layer candidate values according to the first-layer search value, one of a reception signal and a derivative thereof, and one of a channel estimation signal and a derivative thereof; calculating K second-layer candidate values according to the K first-layer candidate values; determining whether to add P second-layer supplemental candidate value(s) and generating a decision; when the decision is affirmative, adding the P second-layer supplemental candidate values, generating P first-layer supplemental candidate values according to the P second-layer supplemental candidate values, and calculating log likelihood ratios (LLRs) according to the (K+P) first-layer and (K+P) second-layer candidate values; and when the decision is negative, calculating LLRs according to the K first-layer and K second-layer candidate values.

A signal detection method for a MIMO-OFDM wireless communication system includes obtaining a channel matrix of each subcarrier through channel estimation for each MIMO-OFDM data packet in a plurality of MIMO-OFDM data packets; receiving a reception vector of each subcarrier; performing MIMO detection for a first OFDM symbol in a MIMO-OFDM pack and channel matrix preprocessing for the channel matrix of each subcarrier to generate a global dynamic K-value table; performing MIMO detection for each subsequent OFDM symbol in the MIMO-OFDM data packet, in which the MIMO detection includes: performing the following steps for each subcarrier of a current OFDM symbol: reading channel matrix preprocessing results and reception vector of the current subcarrier; transforming the reception vector of the current subcarrier into an LR search domain; and performing K-best search for the current subcarrier to obtain an LR domain candidate transmission vector of the current subcarrier, in which a K-value applied to each search layer of the current subcarrier during the K-best search is a global dynamic K-value in the global dynamic K-value table corresponding to the search layer.

Methods and apparatus for processing multichannel signals in a multichannel receiver are described. In one implementation, a plurality of demodulator circuits may provide a plurality of outputs to a processing module, with the processing module then simultaneously estimating noise characteristics based on the plurality of outputs and generating a common noise estimate based on the plurality of outputs. This common noise estimate may then be provided back the demodulators and used to adjust the demodulation of signals in the plurality of demodulators to improve phase noise performance.

Examples pertaining to reference signal sharing in mobile communications are described. An apparatus (e.g., UE) receives a plurality of reference signals comprising a first set of reference signals and a second set of reference signals. The apparatus performs time or frequency tracking based on the plurality of reference signals. Alternatively, the apparatus generates a channel state information (CSI) report associated with the plurality of reference signals and transmits the CSI report to a network.

A signal processing method including the steps of: using a FFT window to process a last symbol of a first sub-frame of a frame to generate a frequency-domain signal, wherein the FFT window has a first start point; performing an IFFT operation on the frequency-domain signal to generate a channel impulse response; performing a channel estimation on the channel impulse response to generate a channel profile; referring to the channel profile of the last symbol of the first sub-frame, an attribute of a start symbol of a second sub-frame and the first FFT window start point to determine a second FFT window start point; using the FFT window having the second start point to process the start symbol of the second sub-frame to generate another frequency-domain signal.