A receiver includes a plurality of equalization modules each configurable to provide a selectable compensation value to a data bit stream received by the receiver, and a control module configured to perform a plurality of back channel adaptations on the data bitstream to achieve a target bit error rate for the receiver, each back channel adaptation being associated with a set of compensation values of the equalization modules, determine a most common set of compensation values derived from the performance of the plurality of back channel adaptations, and determine an optimized set of compensation values based on the most common set of compensation values.

A method for adaptive coding and modulation. The method includes generating a set of mapping functions and transmitting a t.sup.th set of transmit symbols where 1≤t≤T and T is a maximum number of symbol transmissions. Transmitting the t.sup.th set of transmit symbols includes transmitting each transmit symbol in the t.sup.th set of transmit symbols. Each transmit symbol is transmitted by a respective transmitter. Transmitting each transmit symbol includes generating a t.sup.th set of mapped symbols, generating each transmit symbol from the t.sup.th set of mapped symbols, and transmitting each transmit symbol. Generating the t.sup.th set of mapped symbols includes applying a mapping functions subset of the set of mapping functions on a respective data vector. Each mapping function in the mapping functions subset depends on a respective mapped symbol in an r.sup.th set of mapped symbols where 0≤r≤T.

A decision-feedback equalizer (DFE) samples an input signal with respect to a gamut of p reference-voltage levels to place the symbol represented by the input signal within a voltage region. The DFE derives a set of tentative decisions for the voltage region, the set excluding at least one of the possible values for the symbol under consideration. A feedback stage then selects a final decision from among the tentative decisions.

Apparatus and methods for multi-antenna communications are provided. In certain embodiments, a communication system includes an antenna array including a plurality of antenna elements, and a plurality of RF circuit channels each coupled to a corresponding one of the antenna elements. The plurality of RF circuit channels generate two or more analog baseband signals in response to the antenna array receiving a radio wave. The communication system further includes a controllable amplification and combining circuit that generates two or more amplified analog baseband signals based on amplifying each of the two or more analog baseband signals with a separately controllable gain, and that combines the two or more amplified analog baseband signals to generate a combined analog baseband signal.

Apparatus and methods for multi-antenna communications are provided. In certain embodiments, a communication system includes an antenna array including a plurality of antenna elements, and a plurality of RF circuit channels each coupled to a corresponding one of the antenna elements. The plurality of RF circuit channels generate two or more analog baseband signals in response to the antenna array receiving a radio wave. The communication system further includes a controllable amplification and combining circuit that generates two or more amplified analog baseband signals based on amplifying each of the two or more analog baseband signals with a separately controllable gain, and that combines the two or more amplified analog baseband signals to generate a combined analog baseband signal.

An antenna front-end module, method, and information handling system are adapted to the application of a direct-current (DC) bias voltage in relation to an antenna and detect a connection status of the antenna based on a sensed DC voltage. When the connection status corresponds to the antenna being connected, a first transmit power level is configured. When the connection status corresponds to the antenna being disconnected, a second transmit power level is configured. A transmit power boost can be provided such that the first transmit power level is greater than the second transmit power level. The first transmit power level can correspond to a radiative transmission mode, and the second transmit power level can correspond to a conductive transmission mode.

An integrated receiver supports adaptive receive equalization. An incoming bit stream is sampled using edge and data clock signals derived from a reference clock signal. A phase detector determines whether the edge and data clock signals are in phase with the incoming data, while some clock recovery circuitry adjusts the edge and data clock signals as required to match their phases to the incoming data. The receiver employs the edge and data samples used to recover the edge and data clock signals to note the locations of zero crossings for one or more selected data patterns. The pattern or patterns may be selected from among those apt to produce the greatest timing error. Equalization settings may then be adjusted to align the zero crossings of the selected data patterns with the recovered edge clock signal.

A receiver may include a first filter configured to generate a first estimation of a symbol of a received signal and a second filter configured to generate a second estimation of the symbol of the received signal. The receiver may also include a decoder configured to decode the symbol using one of the first estimation and the second estimation and a decision circuitconfigured to select one of the first estimation and the second estimation to provide to the decoder for decoding of the symbol based on a comparison of the first estimation to an estimation threshold.

A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

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.