Silvus Technologies, Inc.

University of California

Interdigital Technology Corporation

Sasken Communication Technologies Limited

Babak Daneshrad

Weijun Zhu

Anish Narendra Shah

Yogendra C Shah

Hun-Seok Kim

Ahmed Mohamed Eltawil

Sudhakar Pamarti

Mansour Rachid

Jean-Francois (jf) Frigon

Karim Mohammed

Christian Oberli

Jatin Bhatia

A method and apparatus for selective programmable filtering using analog circuits with time-varying components (e.g., resistances, capacitances) is presented. An analog front end receives an electronic signal and filters said signal by a passive or active continuous-time filter, having a combination of equivalent memory-less (e.g., resistive) and memory (e.g., capacitive or inductive) elements. A variable resistor circuit allows switching through a range of values to control one or more of the equivalent resistances of the passive or active continuous-time filter. The variable resistors are controlled using a control circuit to periodically modulate the resistances in the continuous-time filter between periodic sampling instances, such as during analog to digital conversion. Such periodic modulation of the resistances in the continuous-time filter allows for the programming and enhancement of the selectivity of said filter.

Sharp programmable filters using periodically time-varying components

Methods and systems for mitigating interference or estimating a covariance matrix in a communication system are disclosed. A method of demodulating a received signal in a communication system can include receiving a first plurality of waveforms, estimating a covariance matrix based on the first plurality of waveforms, determining a spatial filter based on the estimated covariance matrix, receiving a second plurality of waveforms, generating at least one filtered waveform by applying the spatial filter to the second plurality of waveforms, and demodulating the at least one filtered waveform.

Interference mitigation for devices with multiple receivers

Certain disclosed embodiments pertain to suppressing interference in a wireless communication system. For example, a method of suppressing interference can include receiving one or more first signals including components from a plurality of sub-channels. Each of the first signals can be converted into a respective plurality of first sub-band frequency components. A respective spatial filter can be determined for each frequency sub-band using one or more corresponding first sub-band components for each respective spatial filter. One or more second signals including components from the plurality of sub-channels can be received. Each of the second signals can be converted into a respective plurality of second sub-band frequency components. A corresponding plurality of filtered sub-band components can be generated by applying the respective spatial filters to the corresponding second sub-band components for each of the second signals.

Wideband interference mitigation for devices with multiple receivers

Methods and systems for mitigating interference or estimating a covariance matrix in a communication system are disclosed. In some embodiments, a method of demodulating a received signal in a communication system includes receiving a first plurality of waveforms, estimating a covariance matrix based on the first plurality of waveforms, determining a spatial filter based on the estimated covariance matrix, receiving a second plurality of waveforms, generating at least one filtered waveform by applying the spatial filter to the second plurality of waveforms, and demodulating the at least one filtered waveform.

Some embodiments disclosed herein provide a signal decoder with a general purpose calculation engine. A system for decoding signals in a wireless communication system can include: a controller including an instruction counter; a program memory configured to store program code for operating the controller; a general purpose calculation engine configured to perform primitive operations derived from algorithms for decoding a plurality of coded signals received via a plurality of receive antennas; and a data memory connected to the general purpose calculation engine for storing data generated by the general purpose calculation engine while performing the primitive operations.

Signal decoder with general purpose calculation engine

The present invention is related to a generalized rake receiver for a wireless communication system. The rake receiver comprises a plurality of finger correlators and a plurality of escort correlators. Each finger correlator demodulates each multipath components of the transmitted signal. The escort correlator is used for multipath tracking for optimal finger placement and weight estimation for demodulation. The escort correlator is located in vicinity of multipath center and is programmable within a chip and at a resolution finer than a chip. Weight vector is estimated using the estimate of the total base station energy based upon the pilot information from the base stations in soft-handoff.

Generalized rake receiver for wireless communication

A universal rake receiver architecture includes modular independent processing units that can be flexibly programmed to support different modes of operation. The processing units are capable of performing the basic correlation calculations of DS-CDMA and each unit has an internal local memory and controller that controls its mode of operation. Each unit performs the required synchronization and demodulation operations for a multipath of a signal in the digital domain using all-digital frequency and timing correction techniques. Frequency feedback need not be supplied to the analog section of the receiver. Interpolation most preferably is used to find the optimum sampling position of each incoming chip. This independence allows the receiver to be used with one to several antennas without design modifications.

Growing community of inventors

Encino, CA, United States of America

Babak Daneshrad