The present disclosure is directed to simultaneous channel sounding on multiple MLO channels followed by determining phase and amplitude corrections based on channel impulse responses obtained on each MLO channel. The corrections are then used in subsequent extrapolation of channel sounding on one channel to another. In one aspect, a method includes transmitting, on each radio interface of a first multi-link device, a corresponding sounding probe to a second multi-link device; determining, by each radio interface of the first multi-link device, a corresponding channel impulse response based on the corresponding sound probe to yield a plurality of channel impulse responses; determining an offset between the plurality of channel impulse responses; and using the offset during a subsequent extrapolation of a sounding probe on one radio interface to a second radio interface of the first multi-link device.

A method of estimating a wireless channel including determining a value of from a finite set of discrete values for channel estimation in a slot N based on time-selectivity of a channel corresponding to the slot N; estimating the channel according to reference signal symbols received in the slot N; determining a transmit power level in a slot N1, a transmit power level in the slot N, and a power offset ratio; identifying filtered channel coefficients in the slot N1; and computing in real time filtered channel coefficients in the slot N according to a determined set of values applied to generate a subset of equalized QAM symbols in the slot N, the estimated channel according to reference signal symbols received in the slot N, the determined power offset ratio, and the filtered channel coefficients in the slot N1.

A radar system can improve performance by estimating a channel impulse response (CIR) in a way that accounts for noise arising from asymmetric interference. The system transmits a first channel-sounding sequence (CSS) that includes a first pulses and a second CSS that includes second pulses. The second pulses are complements of the first pulses. A first CIR corresponding to the first CSS and a second CIR corresponding to the second CSS are combined to produce an overall CIR that reduces or eliminates artefacts caused by asymmetric interference.

In a general aspect, a set of observed frequency-domain channel responses is filtered to remove noise or distortions that are not related to changes in the physical environment. In some aspects, for each frequency-domain channel response, a time-domain channel response is generated based on the frequency-domain channel response; and a filtered time-domain channel response is generated based on a constraint applied to the time-domain channel response. Additionally, a reconstructed frequency-domain channel response is generated based on the filtered time-domain channel response. An error signal is also generated, and a determination is made as to whether the error signal satisfies a criterion. The error signal can be indicative of a difference between the frequency-domain channel response and the reconstructed frequency-domain channel response. In response to each of the error signals satisfying the criterion, motion of an object in a space is detected based on the set of frequency-domain channel responses.

A battery pack comprises an enclosure; a plurality of network nodes that communicate with each other inside the enclosure and that generate a unique radio frequency (RF) signature; and a special-purpose computer processor that compares an incoming channel impulse response (CIR) of the unique radio frequency (RF) signature corresponding to an incoming packet to a plurality of stored valid RF CIR signatures and executes a resemblance metric to accept or reject the incoming packet.

Techniques for reducing the complexity and power requirements of precompensation units, as well as equalizers, devices, and systems employing such techniques. In an illustrative method for providing high speed equalization, the method comprises: obtaining a channel response that presents trailing intersymbol interference in a signal having a sequence of symbols from a symbol set; determining a distribution of threshold values for a precompensation unit corresponding to said channel response with said symbol set; deriving a reduced set of threshold values from said distribution; and implementing a decision feedback equalizer with a reduced-complexity precompensation unit employing the reduced set of threshold values. In a related illustrative method for providing high speed equalization, the method comprises: obtaining a channel response that presents trailing intersymbol interference in a signal having a sequence of symbols from a symbol set, the channel response and symbol set corresponding to an initial distribution of threshold values for a precompensation unit; deriving a filter that converts the channel response into a modified channel response, the modified channel response and symbol set corresponding to an improved distribution of threshold values in that the improved distribution includes fewer distinct threshold values or reduced spacing between at least some adjacent threshold values; and implementing a decision feedback equalizer with a reduced-complexity precompensation unit employing the threshold values in the improved distribution.

An echo detection circuit for a multi-carrier system includes a memory, a threshold generating circuit and an echo determining circuit. The memory stores a plurality of channel impulse response values of the multi-channel system. The channel impulse response values include a target channel impulse response value, a plurality of preceding channel impulse response values and a plurality of subsequent channel impulse response values; a threshold generating circuit, coupled to the memory, generating a threshold corresponding to the target channel impulse response according to the preceding channel impulse response values and the subsequent channel impulse response values; and an echo determining circuit, coupled to the threshold generating circuit and the memory, comparing the target channel impulse response value with the threshold to determine whether the target channel impulse response value corresponds to an echo path of the multi-carrier system.

Aspects of the present disclosure provide techniques for using cyclic-shifts in code division multiplexing to shift transmitted signals (e.g., reference signals, control signals, and/or data) from different antenna ports of the transmitting device. Particularly, for multiple-input multiple-output (MIMO) systems that multiply the capacity of a radio link by using multiple transmit and receive antennas to exploit multipath propagation, aspects of the present disclosure minimize interference at the receiving device by separating the signals from different antenna ports based on the channel impulse response (or delay spread) of each antenna port of the channel. In some examples, the transmitting device may maximize resource utilization by interleaving the reference signals, control signals, and/or data from a plurality of antenna ports while maintaining adequate spacing between each signal.

Wireless communication wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. An encoding operation encodes and outputs transmitting data (bit string) and a bit converting operation converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into 1 or 0. A modulating operation modulates the bit string inputted from the bit converting operation by using a single modulation mapper and a plurality of data symbols are generated.

Techniques for reducing the complexity and power requirements of precompensation units, as well as equalizers, devices, and systems employing such techniques. In an illustrative method for providing high speed equalization, the method comprises: obtaining a channel response that presents trailing intersymbol interference in a signal having a sequence of symbols from a symbol set; determining a distribution of threshold values for a precompensation unit corresponding to said channel response with said symbol set; deriving a reduced set of threshold values from said distribution; and implementing a decision feedback equalizer with a reduced-complexity precompensation unit employing the reduced set of threshold values. In a related illustrative method for providing high speed equalization, the method comprises: obtaining a channel response that presents trailing intersymbol interference in a signal having a sequence of symbols from a symbol set, the channel response and symbol set corresponding to an initial distribution of threshold values for a precompensation unit; deriving a filter that converts the channel response into a modified channel response, the modified channel response and symbol set corresponding to an improved distribution of threshold values in that the improved distribution includes fewer distinct threshold values or reduced spacing between at least some adjacent threshold values; and implementing a decision feedback equalizer with a reduced-complexity precompensation unit employing the threshold values in the improved distribution.