This disclosure provides channel estimation methods and apparatuses. One method includes: determining Ps initial sample channel matrices that indicate channel states, where the Ps initial sample channel matrices include P1 first sample channel matrices and Ps-P1 second sample channel matrices, the P1 first sample channel matrices are determined based on a previous sample channel matrix or a given reference signal, and Ps is an integer greater than 1; and determining a channel matrix based on the Ps initial sample channel matrices, and obtaining a channel estimation result. Because the P1 initial sample channel matrices in the Ps initial sample channel matrices are determined based on the previous sample channel matrix or the given reference signal, an initial channel estimation result may be provided as an iterative initial sample channel matrix.

In a mobile communication system, a mobile communication apparatus in a vehicle includes a selected resource antenna permitting communication using a selected resource, establishing wireless communication with a target communication apparatus. The mobile communication system includes a propagation path characteristic acquirer section and a resource selector section. The propagation path characteristics acquirer section acquires propagation path characteristics information in association with a future communication position, the propagation path characteristics information being about propagation path characteristics between (i) the target communication apparatus and (ii) a reference antenna equal to the selected resource antenna in antenna characteristics including an antenna format. The resource selector section, based on the propagation path characteristics information, selects a resource to be used in communication at the future communication position before the selected resource antenna of the mobile communication apparatus comes to be placed at the future communication position.

An inter-carrier interference (ICI) mitigation circuit associated with an orthogonal frequency division multiplexing (OFDM) receiver is disclosed. The ICI mitigation circuit comprises an ICI cancellation circuit configured to receive an OFDM symbol associated with an OFDM signal and determine an ICI associated with one or more OFDM subcarriers within the OFDM symbol. The ICI cancellation circuit is further configured to cancel the ICI from the one or more OFDM subcarriers associated with the OFDM symbol, in order to generate a desired OFDM symbol. In some embodiments, the ICI is determined and cancelled at the ICI cancellation circuit, in accordance with a predetermined ICI mitigation algorithm.

The invention relates to the field of terrestrial broadcast transmission, more specifically, to a channel estimation method. A channel estimation method used for estimating a channel of a next carrier signal frame, the channel estimation method comprising: equalizing a carrier of the current signal frame and of the channel of the current signal frame, to obtain a transmission sequence of the current signal frame and a signal-to-noise ratio of the current signal frame, calculating the transmission sequence to get the reference channel, generating an initial channel estimation based on the signal-to-noise ratio of the signal frame, processing the estimated initial channel and the reference channel by an adaptive filtering method, to obtain an estimated channel of next signal frame.

A satellite radio signal receiver includes a receiving section which receives radio signals from satellites and demodulates the signals to identify bits of the demodulated signals as received bits; and a processor. The processor compares each received bit of the satellites with estimated bits which are estimated to be received within a possible deviation range from a current date and time acquired as a reception timing of the received bit to obtain comparison result information between the received bits and the estimated bits in relation to deviations within the possible deviation range with respect to each of the satellites, integrates the comparison result information on the received bits of the satellites, specifies a deviation that satisfies a match condition of the received bits and the estimated bits based on the integrated comparison result information, and acquires date and time information based on the deviation that satisfies the match condition.

A transmission station device includes a training signal generation unit, a CP addition unit, and a transmission beamforming unit that performs transmission beamforming processing in a time domain using a transmission weight for removing inter-antenna interference. A reception station device includes a CP removal unit, a channel estimation unit, and an equalization unit that performs equalization processing for removing inter-symbol interference in a frequency domain using a reception weight. Either of the transmission station device or the reception station device is provided with a weight calculation unit that calculates the transmission weight and the reception weight based on the channel response, an effective CIR length calculation unit that calculates an effective CIR length between antennas, and a CP length setting unit that sets, to the CP length, a maximum CIR length among the CIR lengths of respective items of the reception weight.

An improved receiver design implements a practical method for modeling users in SIC turbo loop multiuser detection architectures, wherein in each loop unsubtracted estimation errors from previous loops are used to appropriately scale the error covariance matrix for each user, thereby accurately representing the remaining residual interference in the data stream for each desired user. The effect of estimation errors in previous interference cancellation operations is thereby minimized, and symbol estimations in successive turbo loops are improved, for example during multiuser MMSE, multiuser MMSE with interference rejection combining (MMSE-IRC), sample matrix inversion (SMI), or any of their adaptive variants (least mean-square, recursive least square, Kalman filter etc.). The estimated residual symbol energy can be computed per symbol, and then applied to entire data streams, to groups of symbols, or to each symbol separately.

The invention relates to the field of terrestrial broadcast transmission, more specifically, to a channel estimation method. A channel estimation method used for estimating a channel of a next carrier signal frame, the channel estimation method comprising: equalizing a carrier of the current signal frame and of the channel of the current signal frame, to obtain a transmission sequence of the current signal frame and a signal-to-noise ratio of the current signal frame, calculating the transmission sequence to get the reference channel, generating an initial channel estimation based on the signal-to-noise ratio of the signal frame, processing the estimated initial channel and the reference channel by an adaptive filtering method, to obtain an estimated channel of next signal frame.

A receiver applies a calibration method to compensate for skew between input channels. The receiver skew is estimated by observing the coefficients of an adaptive equalizer which adjusts the coefficients based on time-varying properties of the multi-channel input signal. The receiver skew is compensated by programming the phase of the sampling clocks for the different channels. Furthermore, during real-time operation of the receiver, channel diagnostics is performed to automatically estimate differential group delay and/or other channel characteristics based on the equalizer coefficients using a frequency averaging or polarization averaging approach. Framer information can furthermore be utilized to estimate differential group delay that is an integer multiple of the symbol rate. Additionally, a DSP reset may be performed when substantial signal degradation is detected based on the channel diagnostics information.

An improved receiver design implements a practical method for modeling users in SIC turbo loop multiuser detection architectures, wherein in each loop unsubtracted estimation errors from previous loops are used to appropriately scale the error covariance matrix for each user, thereby accurately representing the remaining residual interference in the data stream for each desired user. The effect of estimation errors in previous interference cancellation operations is thereby minimized, and symbol estimations in successive turbo loops are improved, for example during multiuser MMSE, multiuser MMSE with interference rejection combining (MMSE-IRC), sample matrix inversion (SMI), or any of their adaptive variants (least mean-square, recursive least square, Kalman filter etc.). The estimated residual symbol energy can be computed per symbol, and then applied to entire data streams, to groups of symbols, or to each symbol separately.