A method for equalizing a signal comprising modulated symbols comprising a block of N received symbols comprises: demultiplexing the N received symbols by factor L to generate a predetermined number L of sub-blocks of symbols, each comprising a version of the N received symbols sub-sampled by factor L, the independent equalization of each sub-block using an identical equalization algorithm, multiplexing the equalized symbols of each sub-block to obtain a block of N equalized symbols, removing instances of interference linked to paths other than two paths of higher power comprising generating an interference term resulting from the influence, on the equalized symbols, of all paths of the channel having the impulse response of the transmission channel except two paths of higher power, subtracting the interference term from the symbols of the block of N received symbols, and, a second equalization step equal to a second iteration of the first equalization step.

A turbo equalization device includes equalization circuitry, which in operation, performs an equalization process M times on an input signal, M being an integer equal to or more than 1; counter circuitry, which in operation, counts an iteration number m that indicates a number of the performed equalization process, m being an integer equal to or more than 0 and equal to less than M; control circuitry, which in operation, determines an iteration number N of a decoding process for the m times equalization processed input signal according to the iteration number m of the equalization process, the decoding process using an error correcting code that uses a belief propagation algorithm, N being an integer equal to or more than 1; and decoding circuitry, which in operation, performs a decoding process N or less times on the m times equalization processed input signal.

A distributed antenna system (DAS) and method are disclosed. The system includes at least one RIM associated with a remote unit. The RIMs and the remote units (RU) are configured for transmitting and receiving test signal over at least one narrow band of frequencies. The system includes a plurality of signal generators associated with a signal path, each signal generator configured for generating a test signal over the at least one narrow band of frequencies; a controller configured to generate a test signal for the signal path; and, an equalizer for adjusting gain for the signal path according to at least one of the narrow band of frequencies.

Embodiments described herein provide a method and apparatus for monitoring and correcting a transmit signal. A first sample is taken before the signal is input to a digital to analog converter (DAC) in a transmit chain. A second sample is taken of the transmit signal after the signal has passed through the power amplifier (PA). The first and second transmit samples are then compared and an equalizer interpolation value is determined. This equalizer interpolation value is applied to the transmit signal before transmission to provide a transmit signal with improved quality. The apparatus includes a feedback receive correction unit; a time domain processor in communication with the feedback receive correction unit; a frequency domain processing equalizer in communication with the time domain processor; an equalizer interpolation unit; an absolute value squaring unit in communication with the equalizer interpolation unit; and a processor for computation of a transmit quality parameter.

Selection of equalization coefficients to configure a communications link between a receiver in a host system and a transmitter in an optical or electrical communication module is performed by a management entity with access to management registers in the receiver and transmitter. Continuous modification of the selected equalization coefficients is enabled on the communications link after the communications link is established to handle varying operating conditions such as temperature and humidity.

An apparatus and method for optimizing the performance of satellite communication system receivers by using the Soft-Input Soft-Output (SISO) BCJR (Bahl, Cocke, Jelinek and Raviv) algorithm to detect a transmitted information sequence is disclosed. A Sliding Window technique is used with a plurality of reduced state sequence estimation (RSSE) equalizers to execute the BCJR algorithm in parallel. A serial data stream is converted into a plurality of data blocks using a serial-to-parallel converter. After processing in parallel by the equalizers, the output blocks are converted back to a serial data stream by a parallel-to-serial converter. A path history is determined using maximum likelihood (ML) path history calculation.

An adaptive finite impulse response (FIR) filter for filtering an I/Q data stream having a sample period. The FIR filter comprises at least one sample-period tap delay configured to delay the I/Q data stream by an integer multiple of the sample period of the I/Q data stream, and at least one sub-sample-period tap delay configured to delay the I/Q data stream by a non-integer multiple of the sample period of the I/Q data stream. A set of adaptive weights is provided and configured to weight samples of the delayed I/Q data stream. An adder is responsive to the weighted samples and configured to combine the weighted samples of the delayed I/Q data streams to generate a filtered I/Q data stream.

Apparatuses and method relating to DFE include a decision feedback equalizer with first and second integrating summers configured to receive an input differential signal. A bias current circuit is configured to alternate biasing of the first and second integrating summers. The first and second integrating summers alternately integrate, during clock signal phases of a clock signal and its complement, for transconductance of the input differential signal to a first output differential signal and a second output differential signal, respectively. The first and second integrating summers alternately drive, during other clock signal phases of the clock signal and its complement, residual voltages of the first output differential signal and the second output differential signal, respectively, to a same voltage level. A first clock signal and a second clock signal are out of phase with respect to one another for interleaving the first output differential signal and the second output differential signal.

A node and a method therein, for authenticating a mobile device over an air interface. The node comprises a transmitter, a processor, and a receiver. The processor is configured to detect the mobile device, to generate a nonce, to determine a key shared with the mobile device and to compute a second MAC based on the generated nonce and the key, and to construct a second training sequence comprising the second MAC. The transmitter is configured to transmit the generated nonce to the mobile device. The receiver is configured to receive a first training sequence comprising a first MAC from the mobile device and to tune the receiving circuits of the receiver, based on the first and second training sequences; and to receive a further message from the mobile device. Further, the processor is configured to decode the further message and authenticate the mobile device or reject the mobile device.

A logging tool is positioned downhole in a wellbore, where the logging tool communicates with a computer on the Earth's surface over an analog signal path. Tool data is received from a sensor associated with the logging tool and encoded into a symbol signal. The symbol signal is transmitted to a receiver system via the analog signal path. The receiver system has one or more filters to filter the symbol signal. The one or more filters includes an equalizer filter indicative of an analog signal path response of the analog signal path. The filtered symbol signal is decoded into second tool data. The second tool data is encoded into second symbols and based on the second symbols, an updated analog signal path response of the analog signal path is generated to update the equalizer filter.