Disclosed is an electronic device, including a housing, a first communication circuit disposed in the housing and configured to support omnidirectional wireless communication, a second communication circuit disposed in the housing and configured to support directional wireless communication using beamforming, a processor disposed in the housing and operatively coupled to the first communication circuit and the second communication circuit, and a memory disposed in the housing and operatively coupled to the processor. The processor may be configured to receive at least one first radio signal through a communication channel from an external device capable of supporting the omnidirectional wireless communication and the directional wireless communication using the first communication circuit, determine a state of the communication channel based on at least part of the at least one first radio signal, and activate the second communication circuit based on at least part of the determined state of the communication channel wherein the second communication circuit is configured to receive a second radio signal from the external device.

Receivers including estimation unit (EU) circuits and related processing techniques for wireless systems are provided. Efficient expressions for quadrature amplitude modulation (QAM) symbol mean and variance calculations are utilized with efficient expressions and implementations that are adaptive to different orders of QAM formats. An EU circuit includes a mean estimation unit (MEU) circuit and/or second moment estimation unit (SEU) circuit. Each estimation unit circuit is configured to receive a variable QAM normalization factor so that the circuit can be adapted to different QAM orders. Each MEU or SEU circuit can be configured for sequential and/or parallel processing. A pool including multiple MEU circuits and/or a pool including multiple SEU circuits is provided in one embodiment, with a control unit for configuring and reconfiguring the pools of circuits for mean and variance estimation for data streams of QAM symbols.

A transmitter includes a shift register, a lookup table, and a digital to analog converter. The shift register is configured to receive an input signal and to output delayed copies of the input signal. The lookup table is configured to store compensation values estimated based on the input signal and the delayed copies of the input signal. The digital to analog converter is configured to output a transmit signal based on the input signal and the compensation values. The compensation values are designed to mitigate distortion of the transmit signal from conversion of the input signal to a digital signal.

A receiver (e.g., for a 10G fiber communications link) includes an interleaved ADC coupled to a multi-channel equalizer that can provide different equalization for different ADC channels within the interleaved ADC. That is, the multi-channel equalizer can compensate for channel-dependent impairments. In one approach, the multi-channel equalizer is a feedforward equalizer (FFE) coupled to a Viterbi decorder, for example, a sliding block Viterbi decoder (SBVD); and the FFE and/or the channel estimator for the Viterbi decoder are adapted using the LMS algorithm.

The present application describes systems and methods of performing self-interference cancellation. According to an embodiment, the method sends a transmit signal through a circulator to substantially isolate the transmit signal from a receiver, with at least a portion of the transmit signal entering a receive path towards the receiver. The method also generates a reflected signal from an antenna. The reflected signal is at substantially less power than an incident power to the antenna. The reflected signal includes a transmitter carrier signal and a transmitter noise. The method also routes a received signal from the antenna to the receiver, and routes the reflected signal through a phase shifter in the receive path. Further, the method combines the reflected, phase shifted transmitter noise with the received signal in the receive path to cancel the portion of the transmit signal that entered the receive path towards the receiver.

A transmitting device includes: a transmission signal generation circuit that generates a transmission signal using a frame format including a legacy short training field (STF), a legacy channel estimation field (CEF), a legacy header field, an enhanced directional multi-gigabit (EDMG) header field, an EDMG-STF, an EDMG-CEF, and a data field; and a transmission circuit that transmits the generated transmission signal using one or more channels, wherein the legacy header field includes a data length field expressed by multiple bits, and the data length field indicates, to a legacy terminal, information related to a data length using all of the multiple bits, and indicates, to an EDMG terminal, information related to a data length using a subset of the multiple bits, and uses the remaining bit or bits to indicate information related to the one or more channels in which the transmission signal is transmitted.

A method of channel estimation in a communication system includes the steps of: receiving at least one input signal associated with at least one data stream, the input signal having reference symbols and data symbols; processing the at least one input signal in a slot-wise manner; performing a channel estimation by taking at least one reference symbol per input signal into account, which is used to equalize the respective input signal and to assign the symbols to the at least one data stream, thereby generating a processed signal for each independent data stream, and processing further the processed signal while performing an additional channel estimation for each independent data stream, wherein the reference symbols and the data symbols are taken into account for the additional channel estimation. Further, a signal processing system is described.

Techniques to manage dwell times for pilot rotation are described. An apparatus may comprise a memory configured to store a data structure with a set of modulation and coding schemes (MCS) available to an orthogonal frequency division multiplexing (OFDM) system, each MCS having an associated pilot dwell time. The apparatus may further comprise a processor circuit coupled to the memory, the processor circuit configured to identify a MCS to communicate a packet using multiple subcarriers of the OFDM system, and retrieve a pilot dwell time associated with the MCS from the memory, the pilot dwell time to indicate when to shift a pilot tone between subcarriers of the multiple subcarriers during communication of the packet. Other embodiments are described and claimed.

A method includes generating a two-dimensionally filtered pilot tone based on a plurality of received pilot tones received using a first subcarrier of each of a plurality of received OFDM symbols and a plurality of data symbols received using a second subcarrier of each of the plurality of received OFDM symbols. The plurality of OFDM symbols is received sequentially over a plurality of OFDM symbol times. The method may include generating inverse channel coefficients based on the two-dimensionally filtered pilot tone. The method may include applying the inverse channel coefficients to a subsequently received OFDM symbol to recover data encoded in the subsequently received OFDM symbol. Generating the two-dimensionally filtered pilot tone may use at least one least-mean-squares filter.

A receiver (e.g., for a 10 G fiber communications link) includes an interleaved ADC coupled to a multi-channel equalizer that can provide different equalization for different ADC channels within the interleaved ADC. That is, the multi-channel equalizer can compensate for channel-dependent impairments. In one approach, the multi-channel equalizer is a feedforward equalizer (FFE) coupled to a Viterbi decorder, for example, a sliding block Viterbi decoder (SBVD); and the FFE and/or the channel estimator for the Viterbi decoder are adapted using the LMS algorithm.