A fractional delay estimation module estimates a delay of a section of a forward processing path between a first point and a second point. The fractional delay estimation component determines an integer component and a fractional component of a first path delay based on a transform of a first vector inserted into the forward processing path at the first point and based on a transform of a first feedback vector received from a feedback path, determines an integer component and a fractional component of a second path delay in the forward processing path based on a third transform of a third vector inserted into the forward processing path at the second point and based on a fourth transform of a second feedback vector received from the feedback path, and further determines the estimated delay of the section based on a difference between the first and second path delays.

A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

A communication device includes a channel estimation unit configured to estimate an impulse response based on signals of sound waves received by each of a plurality of hydrophones, a long delay removal unit configured to remove a long-delay impulse response from the impulse response to generate a post-removal impulse response, a weighting factor calculation unit configured to calculate a weighting factor based on the post-removal impulse response, and a synthesizing unit configured to synthesize the signals received by each of the plurality of hydrophones based on the weighting factor.

A communications system includes a transmission station configured to transmit data to plural reception stations by non-orthogonal multiplexing. The transmission station is further configured to transmit pilot signals to the plurality of reception stations by respective transmission powers corresponding to respective transmission powers of the data. The communications system further includes a reception station included in plural reception stations and configured to estimate the respective transmission powers of the data based on the pilot signals transmitted by the transmission station. The reception station is further configured to perform channel estimation between the transmission station and the reception station based on the estimated respective transmission powers.

A method for estimating performance of a serial communication channel using processing circuits. The channel is configured to transmit a binary input stream from a transmitting end to an output stream at a receiving end. The method includes modeling by the processing circuits the channel at the receiving end as a first finite impulse response (FIR) system. The modeling includes estimating a cursor pulse response of the first FIR system by analyzing the output stream received at the receiving end, and estimating one or more pre-cursor or post-cursor pulse responses of the first FIR system from the received output stream using the estimated cursor pulse response. The method further includes determining by the processing circuits a performance metric by using the estimated one or more pre-cursor or post-cursor pulse responses.

The present disclosure relates to an equalizer training unit for deriving equalization parameters for compensating data-dependent distortion in received samples by use of a training sequence including a sequence p>1 times and cyclically comprising N sub-sequences of respective combinations of L time-domain symbols of a modulation scheme, wherein the N sub-sequences are cyclically arranged in a selected order and such that L−1 symbols of a respective sub-sequence overlap with symbols in the preceding and following sub-sequences. The present disclosure further relates to a training sequence generator unit for generative the training sequence and an equalizer employing the equalizer training unit.

Channel estimation where at least two sets of multipath components for a reception range are formed by applying spatial filtering to reference signal information measured by a communication device. Each set of multipath components comprises a number of multipath components that is less than the number of multipath components for the range. Separate parameter estimations are performed on the at least two sets of multipath components. The communication device may be a mobile device, and measurements may be provided by the mobile device in multiple of locations.

A detector in a mobile device receives input from a modem, determines whether the mobile device is indoor or outdoor based on the modem-supplied input, and stores in memory a binary value to indicate an indoor-outdoor state. In some embodiments, the detector extracts a feature from the modem-supplied input, and uses the extracted feature with a statistical classifier, to output an indoor-outdoor state and an associated probability of correctness of the indoor-outdoor state. In other embodiments, the detector determines whether the mobile device is indoor or outdoor based at least on the feature extracted to characterize temporal distribution of the wireless signal, by using a prior value of the state being indoor or outdoor.

A method for monitoring a communication network, which includes a plurality of processing units which communicate with one another via a communication medium, a channel of the communication medium being measured using channel estimation; from a result of the channel estimation, a characteristic variable being produced; and, with the aid of the characteristic variable, a decision is made as to whether a manipulative change of the communication network has occurred.

A method for detecting a signal by a signal receiving apparatus is provided. The method includes detecting a part of block diagonal matrices included in a diagonal matrix based on at least one channel impulse response (CIR) for a received signal, detecting remaining block diagonal matrices excluding the part of block diagonal matrices from among block diagonal matrices included in the diagonal matrix, estimating modulation symbols from the received signal based on the diagonal matrix, generating a block diagonal matrix by multiplying one of second matrices included in a first matrix, which is generated by applying a circular extension scheme to a fourth matrix including third matrices, by a fast Fourier transform (FFT) matrix, generating a third matrix for one of the estimated modulation symbols, the third matrix includes vectors for channelization codes, and generating a vector based on the channelization codes or the at least one CIR.