Patent classifications
H04L25/03006
Circuits and methods for DFE with reduced area and power consumption
A 1/n-rate decision feedback equalizer (DFE) and method include a plurality of branches. Each branch includes a summer circuit configured to add a feedback signal to a received input, and a latch configured to receive an output of the summer circuit in accordance with a clock signal. A feedback circuit includes a multiplexer configured to receive as input, an output of each branch, the multiplexer having a clocked select input and configured to multiplex the output of each branch to assemble a full rate bit sequence, and a filter configured to provide cancellation of intersymbol interference (ISI) from the received input to be provided to the summer circuit of each branch.
Systems/methods of spectrally efficient communications
First and second receivers are used to receive respective first and second signals, to process said first and second signals and provide respective first and second measures thereof to respective first and second transmitters. The first and second transmitters are configured to launch the first and second measures, respectively, each comprising a desired component that has originated at a desired source, and an interference component that has originated at an interfering source. The first and/or second transmitters are configured to process and launch the respective first and second measures, properly conditioned, so that upon interception thereof by a receiving element the interference components thereof add destructively and substantially cancel (or at least partially cancel) each other, whereas the desired components avoid substantial cancellation owing to a phase relationship therebetween that differs relative to a phase relationship between the interference components.
METHOD AND APPARATUS FOR RECEIVING DATA IN COMMUNICATION SYSTEM SUPPORTING MULTIPLE INPUT MULTIPLE OUTPUT SCHEME
The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as a long term evolution (LTE). A method for receiving data includes selecting one of reception schemes, and receiving data based on the selected reception scheme, wherein the reception schemes includes a scheme of determining an integer matrix based on channel values estimated for channels, and decoding symbols received through the channels based on the determined integer matrix, and a scheme of detecting, for each channel, a sum of symbols received from each of the channels during a preset time based on integer matrixes which are determined based on each of the channel values, retransforming the sum of the symbols detected for each channel based on at least one of the integer matrixes, and decoding the retransformed sum of the symbols for each channel.
SUCCESSIVE SIGNAL INTERFERENCE MITIGATION
A radar sensing system for a vehicle includes a transmitter, a receiver, and an interference mitigation processor. The transmitter transmits radio signals. The receiver receives radio signals. The received radio signals include reflected radio signals that are each transmitted radio signals reflected from objects in the environment. The receiver also down-converts and digitizes the received radio signals to produce a baseband sampled stream. The interference mitigation processor produces a second received radio signal that includes reflected radio signals that are transmitted radio signals reflected from a first object. The interference mitigation processor uses the second received radio signal to remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object to produce a modified baseband sampled stream. The receiver uses the modified baseband sampled stream to detect a second object more distant than the first object.
SYSTEMS AND METHODS FOR PHASE NOISE MITIGATION IN OPTICAL SUPERCHANNELS
A receiver architecture is described for phase noise compensation in the presence of inter-channel interference (ICI) and inter-symbol interference (ISI), particularly for time-frequency packing (TFP) transmissions. The receiver includes a coarse phase noise (PN) estimator, a PN compensation module, an ICI cancellation module, an ISI compensation module, a FEC decoder, and an iterative PN estimator. The iterative PN estimator receives log likelihood ratio (LLR) information from the decoder and provides an iterative PN estimation to the PN compensation module. The decoder also provides LLR to the ISI compensation module, and to at least one other receiver for another subchannel that is immediately adjacent in frequency. The ICI cancellation module receives decoder output from at least one adjacent subchannel, which the ICI cancellation module uses to provide a ICI-cancelled signal.
OPTICAL DEVICES FOR THE CONSTRUCTION OF COMPACT OPTICAL NODES
Example embodiments of the present invention relate to optical wavelength directing devices used to construct compact optical nodes.
Variable equalizer and method for controlling variable equalizer
In order to realize a variable equalizer which is compact and has a wide range of tilt level adjustment, this variable equalizer is provided with a first optical equalizer group including a plurality of first equalizers having mutually different tilt amounts, a second optical equalizer group including a plurality of second equalizers, and an optical element for forming the optical path of an optical signal so that an inputted optical signal is outputted passing through a selected first optical equalizer and a selected second optical equalizer, at least one of the plurality of second optical equalizers having a tilt amount different from any of the plurality of first optical equalizers.
Methods, systems, and computer program products for adaptive channel estimation and equalization in a multicarrier communication system
Methods and systems are described for adaptive channel estimation and equalization in a multicarrier communication system. In one aspect, a channel estimation in a multicarrier communication system is determined. A prediction error is determined based on a difference between the channel estimation and a reference signal. An equalization matrix is formed based on the prediction error.
DATA SYNCHRONIZATION IN OPTICAL NETWORKS AND DEVICES
Joint estimation of the framer index and the frequency offset in an optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. By identifying the beginning of the header portion of a data frame, the receiver can then process data received from the transmitter in a manner synchronous to the manner in which the data was transmitted by the transmitter.
CIRCUITS AND METHODS FOR TRANSCEIVER SELF-INTERFERENCE CANCELLERS
Self-interference cancellers are provided. The self-interference cancellers can include multiple second-order, N-path G.sub.m-C filters. Each filter can be configured to cancel self-interference on a channel of a desired bandwidth. Each filter can be independently controlled using a variable transmitter resistance, a variable receiver resistance, a variable baseband capacitance, a variable transconductance, and a variable time shift between local oscillators that control switches in the filter. By controlling these variables, magnitude, phase, slope of magnitude, and slope of phase of the cancellers frequency responses can be controlled for self-interference cancellation. A calibration process is also provided for configuring the canceller.