H04L25/025

HIGH SPEED SIGNALING SYSTEM WITH ADAPTIVE TRANSMIT PRE-EMPHASIS

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.

Self-interference channel estimation system and method

The present application describes a method for characterizing a self-interference channel of a frequency division duplex transceiver including a transmitter and a receiver. The method includes transmitting, from a transmitter of a frequency division duplex transceiver in a transmission band, a transmission signal including a message signal and a swept tone that changes frequency from below an upper edge to above a lower edge of a reception band of a receiver, the self-interference channel being defined between the transmitter and the receiver of the frequency division duplex transceiver, such that at least a portion of the message signal leaks into a signal received the receiver, determining, at an infinite impulse response (IIR) filter of the receiver, an infinite impulse response of the self-interference channel based upon a reception of the swept tone swept at each frequency in the reception band, and estimating the self-interference channel, based upon the infinite impulse response.

SYSTEM AND METHOD FOR ENHANCED CHANNEL ESTIMATION USING TAP-DEPENDENT FREQUENCY OFFSET (FO) ESTIMATION
20170257246 · 2017-09-07 ·

Apparatuses (and methods of manufacturing same), systems, and methods for channel interpolation/estimation and/or frequency tracking suitable for a receiver in a high speed single frequency network (HS-SFN) scenario are described. In one aspect, an estimated frequency offset (FO) correction is calculated for a received signal using at least an FO estimation provided by an automatic frequency control (AFC) in a first feedback loop and a channel estimate is calculated using at least the estimated FO and one or more channel parameter estimates from the AFC in a second feedback loop. In another aspect, a phase locked loop (PLL) receives an lth orthogonal frequency division multiplexing (OFDM) symbol and produces a per-tap phase value for each tap i of the lth OFDM symbol. The per-tap phase values of the lth OFDM symbol are used to generate the PLL output, which is also used as input to a feedback loop.

SELF-INTERFERENCE CANCELLATION ANTENNA SYSTEMS AND METHODS

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.

HIGH-SPEED RECEIVER ARCHITECTURE

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 decoder, 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.

High speed signaling system with adaptive transmit pre-emphasis

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.

Methods and nodes in a wireless communication network

Receiver and method in a receiver, for iterative channel estimation and data decoding of signals received from a radio network node, located in a wireless communication network. The method comprises detecting a signal of the radio network node, performing channel estimation of the detected signal, based on iterative application of a Space Alternating Generalized Expectation and maximization, SAGE, algorithm, determining a channel/link quality, based on the performed channel estimation and the estimated channel parameters, selecting Multiple-Input and Multiple-Output, MIMO, detector, based on the determined channel quality, determining to enable and/or disable, respectively, soft-Iterative Channel Estimation, soft-ICE, based on the determined channel quality, and iterating the performed channel estimation for a predetermined number of times.

Device and method for handling channel estimation

A communication device includes: a detecting unit, performing a mobility detection in a time interval to generate a detection result; a selecting unit, selecting a channel estimation method from a plurality of channel estimation methods according to the detection result; and a channel estimating unit, coupled to the selecting unit, performing a channel estimation on a channel for receiving a signal according to the selected channel estimation method.

System and method for spectrally efficient pilot and detector design in delay-doppler domain for OTFS-based NR (new radio) IoT and massive machine tomachine (M2M) communications

A spectrally efficient low complex Orthogonal Time Frequency Space (OTFS) modulation-based transceiver system and method is provided. The system and method are developed for uplink and downlink wireless communication for resource-constrained IoT and M2M devices. The transceiver system includes at least one transmitter configured to transmit bit stream using adaptive Orthogonal Time Frequency Space (OTFS) frame with selectively embedded pilot depending on mobility condition for improving spectral efficiency and at least one receiver configured to dispose onto IoT devices for receiving the transmitted bit stream. The receiver updates the transmitter about mobility condition of said at least one receiver through a control channel.

Self-interference cancellation antenna systems and methods

The present application describes systems and methods of performing self-interference cancellation. Such systems may include generating a transmit signal along a transmit path of a transceiver, where the transmit signal can be sent through a circulator to isolate the transmit signal from a receiver. The transmit signal may be transmitted from an antenna, and a signal may be reflected from the antenna, where the reflected signal may be at less power than an incident power to the antenna, and where the reflected signal may include a transmitter carrier signal and a transmitter noise. A received signal may be routed from the antenna to the receiver, the reflected signal may be routed through a filter and a phase shifter, and the signal may be combined with the received signal in the receive path to cancel the portion of the transmit signal that entered the receive path towards the receiver from the circulator.