A method and apparatus for processing a signal to generate equalizer codes, which are used to control equalization of the signal, that comprises processing the signal to identify the eyes of the signal, and for each eye, calculating an eye height and calculating a noise value. For each eye, squaring the eye height to generate an eye height product and dividing the eye height product by the noise value to generate a Q.sup.2 value. Using the calculated Q.sup.2 values optimizing, through adaptation, the equalizer codes. Calculating the noise values may include calculating an ISI value for each band of the signal and then calculating the eye height for each eye as the difference between the adjacent upper average value and the adjacent lower average value. Then, for each eye, calculating a noise value by summing the ISI value for the band above the eye and the band below the eye.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, an indication that one or more channel condition parameters that are associated with uplink channel estimations are to be signaled to the UE to be used for downlink channel estimations. The UE may receive, from the base station, a report of the one or more channel condition parameters that are associated with the uplink channel estimations. Numerous other aspects are described.

An analog-to-digital conversion circuit includes; a first analog-to-digital converter (ADC), a second ADC and a third ADC collectively configured to perform conversion operations according to a time-interleaving technique, and a timing calibration circuit configured to calculate correlation values and determine differences between the correlation values using first samples generated by the first ADC, second samples generated by the second ADC, and third samples generated by the third ADC during sampling periods, wherein the timing calibration circuit is further configured to control a phase of a clock signal applied to the second ADC in response to a change in absolute value related to the differences generated during the sampling periods.

A network transceiver device is provided, including at least two variable gain amplifiers (VGAs), and at least two sets of analog digital converters (ADCs), each set including ADCs coupled to an output of one of the VGAs, the sets being arranged in VGA-specific channels. The device includes a plurality of feed-forward equalizers (FFEs), each FFE being coupled to receive an output of one of the ADCs in one of the VGA-specific channels. Each FFE is configured to adaptively equalize the output received from the ADCs utilizing a first equalization coefficient subset with coefficient values that are common to all FFEs, and a second equalization coefficient subset that is channel specific and that has a first set of coefficient values for a first VGA-specific channel and a second set of coefficient values for a second VGA-specific channel, the sets of coefficient values being computed independently.

A fast equalization method is provided, which includes: storing a receive parameter and a transmit parameter, of each of a primary chip and a secondary chip, that meet a link stability requirement and that are obtained when link equalization is previously performed; and when determining that link equalization needs to be performed, configuring, as first fast equalization timeout duration, a larger value in initial fast equalization timeout duration of the primary chip and initial fast equalization timeout duration of the secondary chip, and invoking the foregoing receive and transmit parameters, so that the primary chip and the secondary chip perform a current time of link equalization based on the first fast equalization timeout duration and the foregoing transmit and receive parameters.

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.

A communication system includes a first device, a second device, and a cable that connects the first device and the second device, and the cable stores cable information of the cable. A link training method includes: obtaining device information of the first device, obtaining the cable information from the cable, and obtaining device information of the second device; and performing link training between the first device and the second device based on the device information of the first device, the cable information, and the device information of the second device.

A conformance testing method including: obtaining a testing symbol pattern in an optical signal; performing equalization compensation on the testing symbol pattern; generating a testing eye pattern; calculating a value of a first parameter based on the testing eye pattern and a noise enhancement coefficient, where the first parameter is used to determine a transmitter dispersion eye pattern closure degree of the optical transmitter; and when the value of the first parameter is less than or equal to a preset threshold, determining that conformance testing on the optical signal succeeds.

Various embodiments disclosed herein provide for a reciprocity based channel state information acquisition scheme for frequency division duplex wireless communications systems. By converting channel state information from a traditional frequency-time domain to a Delay-Doppler domain, the channel state information feedback overhead can be reduced since the multi-path of radio propagation is reciprocal in terms of each ray and each cluster of antenna elements. Since the surrounding objects create the same multipath fading for both uplink and downlink transmissions, modeling the channel state information in the Delay-Doppler domain, and adjusting the sign of the Doppler value (negative/positive) can account for the multipath characteristics in both uplink and downlink.

A method and system for providing sub-band whitening are herein provided. According to one embodiment, a method includes deriving an estimated noise plus interference variance (NIVar) based on at least one legacy-long training field (LLTF) symbol from an LLTF signal; and updating an interference whitening (IW) factor by using a sub-band NIVar.