Noise and interference may be estimated at a user equipment (UE) in a system that may support transmissions having different transmission time intervals (TTIs). The UE may perform a channel estimation for a first set of transmissions having a first TTI based at least in part on an estimated interference from a second set of transmissions having a second TTI that is shorter than the first TTI. The UE may perform channel estimation for orthogonal frequency division multiplexing (OFDM) symbols of the first set of transmissions. The first set of transmissions may then be demodulated based at least in part on the channel estimation for the first set of transmissions. Noise and interference may also be estimated based on one or more null tones within one or more OFDM symbols of the allocated resources.

A multiple-input multiple-output (MIMO) wireless transceiver with “N” transmit and receive chains and a bandwidth evaluation circuit, a chain partitioning circuit and a switchable radio frequency ‘RF’ filter bank. The bandwidth evaluation circuit evaluates both the utilization of the WLAN(s) and any remaining communications channels and determines whether to operate the MIMO chains synchronously as a single radio or asynchronously as multiple radios. The chain partitioning circuit either partitions subsets of the MIMO chains for asynchronous operation as distinct radios or combines all MIMO chains for synchronous operation as a single radio. The switchable RF filter bank is responsive to a partitioning of subsets of the chains into distinct radios to add RF filters to a RF portion of the chains to isolate each radio from one another, and responsive to a combining of all MIMO chains into a single radio to remove all RF filters.

This application relates to the mobile communications field, and in particular, to a data sending method in a wireless communications system. A first device generates a signal before DFT transform is performed including 2×M signal elements. The 2×M signal elements include elements in two element groups A and B, the elements in the two element groups respectively meet same-number repetition and inverse-number repetition characteristics, and the 2×M signal elements further include another element group C that does not need to meet the same-number repetition/inverse-number repetition characteristics. The element in the element group A and an element in the element group C are multiplexed before DFT, and there is an interval, so that the element group A is not interfered by the element group B or the element group C.

The embodiments herein use a factorization based technique for determining filter coefficients for a subset of the subcarriers in a wireless frequency band. Once the filter coefficients for the subset of the subcarriers are calculated, the network device uses these filter coefficients to identify the filter coefficients in a neighboring subcarrier. To do so, the network device uses pseudo-inverse iteration to convert the already calculated filter coefficients into filter coefficients for a neighboring subcarrier. The network device can repeat this process for the next set of neighboring subcarriers until all the filter coefficients have been calculated.

A receiver is configured to capture a plurality of linearly distorted OFDM symbols transmitted over a signal path. The receiver forms the captured OFDM symbols into an overlapped compound data block that includes payload data and at least one pseudo-extension, processes the overlapped compound block with circular convolution in the time domain using an inverse channel response, or frequency domain equalization, to produce an equalized compound block, and discards end portions of the equalized block to produce a narrow equalized block. The end portion corresponds with the pseudo-extension, and the narrow block corresponds with the payload data. The receiver cascades multiple narrow equalized blocks to form a de-ghosted signal stream of OFDM symbols. The OFDM symbols may be OFDM or OFDMA, and may or may not include a cyclic prefix, which will have a different length from the pseudo-extension.

This application provides a reference signal communication method and communication apparatus. The method includes determining a resource block offset of a frequency domain position of a phase tracking reference signal (PTRS) based on a frequency domain density of the PTRS, an identifier of a terminal device, and a first bandwidth, in accordance with a ratio of the first bandwidth to the frequency domain density of the PTRS being a non-integer. The first bandwidth is a bandwidth scheduled by a network device for the terminal device. The method further includes sending or receiving the PTRS based on the resource block offset of the frequency domain position of the PTRS.

A method and system for providing sub-band whitening are herein provided. According to one embodiment, a method estimating an interference whitening (IW) factor based on a legacy-long training field (LLTF) signal, updating the estimated IW factor during transmission of a data symbol, and scaling the data symbol based on the updated IW factor and the estimated IW factor.

A method of a data transmission apparatus applied in high-speed wired network includes: performing analog-to-digital conversion operation upon a time-domain analog training data signal transmitted from a link partner device to generate a time-domain digital training data signal; converting the time-domain digital training data signal into a frequency-domain training data signal; performing a frequency-domain feed-forward equalization (FFE) operation upon the frequency-domain training data signal to generate a frequency-domain FFE resultant signal; converting the frequency-domain FFE resultant signal into a time-domain FFE resultant signal; generating a difference resultant signal according to the time-domain FFE resultant signal and a feed-back equalization (FBE) resultant signal; receiving the difference resultant signal to generate a slicer resultant signal; and using the FBE operation to generate the FBE resultant signal according to the slicer resultant signal.

An adaptive filter includes a frequency domain adaptation block that analyzes a statistic of coefficient movement in the frequency domain. The adaption block adjusts, in the frequency domain, a parameter (step size or leakage factor) that affects speed of convergence of the adaptive filter based on the analyzed statistic of filter coefficient movement. The filter includes an associated coefficient, statistic of coefficient movement, and parameter for each frequency bin. The coefficients may be complex numbers, and separate real and imaginary statistics and parameters are maintained. The statistic may be direction counts of the filter coefficient movement. The step size may be adjusted to a predetermined minimum value when the current direction of movement of the filter coefficient is different than the predominant direction and otherwise the step size is adjusted approximately proportionally to an amount of predominance by a value based on a direction count of the filter coefficient movement.

Apparatuses, systems, and methods for transmitting and multiplexing chirp signals for communications are provided. An example apparatus includes an antenna, a radio, and processing circuitry. The radio may be configured to transmit and receive wireless communications via the antenna, and the processing circuitry configured to establish a wireless communications link with a receiving communications device. The signaling transmitted by the antenna via the radio as controlled by the processing circuitry may include a plurality of sequenced chirp signals within an orthogonal frequency division multiplexing (OFDM) framework.