Apparatus and methods for link adaptation for downlink transmissions in which the quality of the downlink radio channel is predicted with improved accuracy. For example, predicted channel gains are determined based on uplink transmissions on a per frequency sub-band basis and these predicated channel gains are then used in a link adaptation process for a downlink transmission.

Apparatus and methods for phase noise mitigation in wireless systems and networks. In one embodiment, the apparatus and methods provide enhanced wireless services which provide enhanced performance to 5G millimeter wave system entities base stations (gNodeBs) and their backhaul in support of low-latency and high-throughput operation of these components and the network as a whole. In one variant, an enhanced phase noise mitigation mechanism is provided which has a robust performance in operating in very high frequencies such as millimeter wave spectrum. In yet other implementations, the methods and apparatus described herein can be utilized with respect to mobile devices such as between 5G NR millimeter-wave capable UEs and corresponding gNBs.

A device and method of operation for digital compensation of dynamic distortion. The transmitter device includes at least a digital-to-analog converter (DAC) connected to a lookup table (LUT), a first shift register, and a second shift register. The method includes iteratively adjusting the input values via the LUT to induce changes in the DAC output that compensate for dynamic distortion, which depends on precursors, current cursors, and postcursors. More specifically, the method includes producing and capturing average output values for each possible sequence of three symbols using the shift register and LUT configuration. Then, the LUT is updated with estimated values to induce desired output values that are adjusted to eliminate clipping. These steps are performed iteratively until one or more check conditions are satisfied. This method can also be combined with techniques such as equalization, eye modulation, and amplitude scaling to introduce desirable output signal characteristics.

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.

Embodiments of this application disclose a phase detection method, a phase detection circuit, and a clock recovery apparatus. The method includes: receiving a first signal, and deciding a (2M1) level of the first signal to obtain a decision result, where the first signal is a (2M1)-level signal, and M is a positive integer: obtaining a response amplitude parameter of a transmission channel; extracting clock phase information in the first signal based on the first signal, the decision result, and the response amplitude parameter; and determining output clock phase information based on at least three decision results and at least three pieces of clock phase information in at least three symbol periods. According to the foregoing method, a stable phase detection gain can be achieved when a clock phase is tuned to a pulse response edge

The present disclosure relates to channel estimation, at a receiving device of a communication system employing a (re)configurable surface. The channel estimation includes beamforming search to obtain trained reflection coefficients of the configurable surface and an angle of arrival, AoA, of the signals at the receiving device. Then, based on the configurable surface and the obtained AoA at the receiving device, reflection coefficients of the configurable surface are derived for an ideal channel portion between the transmitting device and the configurable surface. According to a relation between the trained reflection coefficients and the estimated reflection coefficients, the estimation of the characteristics of a channel between the transmitting device and the configurable surface is performed. The channel estimation may be employed in user mobility tracking

A method for estimating baseline in a signal, the signal being represented by input signal data (I(x.sub.i)), includes estimating a baseline contribution (I.sub.2(x.sub.i)) in the signal to obtain baseline estimation data (f(x.sub.i)), wherein the baseline estimation data (f(x.sub.i)) are computed as a fit to at least a subset of the input signal data (I(x.sub.i)) by minimizing a least-square minimization criterion (M(f(x.sub.i))). Deblurred output signal data (O(x.sub.i)) are obtained based on the baseline estimation data (f(x.sub.i)) and the input signal data (I(x.sub.i)). The least-square minimization criterion (M(f(x.sub.i))) comprises a penalty term (P(f(x.sub.i))).

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 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.

Disclosed is a signal source estimation method and apparatus performing the same, the signal source estimation method including acquiring first reception signals received by first receivers, among signals radiated from signal sources, selecting second receivers receiving reception signals to be used to estimate the signal sources, from among the first receivers based on the first reception signals, and detecting the number of signal sources based on second reception signals received by the second receivers.