Interdigital Technology Corporation

David K Mesecher

Alexander M Jacques

Alexander Reznik

Donald M Grieco

Gary Cheung

Fatih M Ozluturk

Gary R Lomp

Jeffrey S Polan

Fatih M &Ouml;zl&uuml;t&uuml;rk

Rui Yang

Leonid L Kazakevich

Ramon Cerda

Leonid Kazarkevich

Ramón Cerda

Faith M Özlütürk

Leonid Kazerkevich

Grieco Donald

A method and apparatus used to transmit and receive weighted data transmissions over a plurality of antennas using a plurality of different pilot signals. Different pilot signals are produced and a different pilot signal of the plurality of pilot signals is transmitted on each of a plurality of antennas. Each of the pilot signals is derived from a pseudo noise (PN) sequence and a bit sequence of the PN sequence for each of the pilot signals is different. A plurality of data streams are produced in which each of the data streams has data bits combined with bits of a PN sequence. The data streams are weighted in response to weight information received from a receiving device and the plurality of weighted data streams are transmitted using the plurality of antennas.

Interference cancellation in a spread spectrum communication system

A code division multiple access communication system has a base station with a plurality of transmitting antennas. From each transmitting antenna of the base station, a pilot signal is transmitted having a different chip sequence than the other transmitting antenna. At a user equipment, the transmitted pilot signals are received from each transmitting antenna. A weight adjustment is derived in response to the received transmitted pilot signals. The user equipment transmits the weight adjustment to the base station. The transmitted weight adjustment is received from the user equipment. A data signal is processed to produce a plurality of versions of the data signal. At least a portion of each processed data signal has a different chip sequence than the other processed data signal version. At least one processed data signal version is weighted by a weight value adjusted in response to the received transmitted weight adjustment. From each transmitting antenna, a different one of the data signal versions is transmitted and the transmitted data signal versions are received at the user equipment.

Code division multiple access transmission antenna weighting

A code division multiple access communication system transmits a pilot and traffic signal over a shared spectrum. The pilot and traffic signal have an associated code and are received over the shared spectrum. The received signals are sampled and the samples are delayed to produce a window. A weighted value for each despread pilot code window sample is determined using an adaptive algorithm. Each window sample is despread with a traffic code. Each despread traffic code window sample is weighted according to a weight corresponding to its respective pilot code sample.

A method for receiving at least one of a plurality of channels in a communication signal includes receiving a spread spectrum communication signal, demodulating the spread spectrum communication signal using a rake receiver and a pseudo-noise pilot signal for a selected channel, despreading the demodulated signal of a selected channel, performing a QPSK hard decision in association with a complex conjugate of the despread signal to produce a correction signal, and mixing the correction signal to a rake receiver output to remove relative phase error without an absolute phase reference, to produce a corrected signal.

Receiver for producing phase corrected signals

A wireless transmit/receive unit (WTRU) for carrier offset recovery. An adaptive matched filter produces a filtered signal. A rake receiver provides relative path values of multipath components. A mixer generates channel impulse response estimates. A channel despreader despreads the filtered signal using the pseudo-noise signal generated to produce a despread channel signal of the selected channel. A pilot channel despreader despreads the filtered signal using a pseudo-noise signal generator to produce a despread pilot signal of the pilot channel. A hard decision processor determines a symbol value of the despread channel signal. A complex conjugate processor generates a complex conjugate of the symbol value as a correction signal. A phase-locked loop produces a phase correction signal to recover carrier offset.

Wireless transmit/receive unit (WTRU) for carrier offset recovery

A base station for carrier offset recovery. An adaptive matched filter produces a filtered signal. A rake receiver provides relative path values of multipath components. A mixer generates channel impulse response estimates. A channel despreader despreads the filtered signal using the pseudo-noise signal generated to produce a despread channel signal of the selected channel. A pilot channel despreader despreads the filtered signal using a pseudo-noise signal generator to produce a despread pilot signal of the pilot channel. A hard decision processor determines a symbol value of the despread channel signal. A complex conjugate processor generates a complex conjugate of the symbol value as a correction signal. A phase-locked loop produces a phase correction signal to recover carrier offset.

Base station for carrier offset recovery

A first reference signal and a first data signal are transmitted from a first antenna of a base station and a second reference signal and a second data signal are transmitted from a second antenna of the base station. The first and second antennas are difference antennas. The first and second reference signals having different codes and the first and second data signals having different codes. The received first and second reference signals are combined using an adaptive algorithm producing adaptive algorithm weights. Data from the first and second data signals is recovered by combining the first and second data signal in response to adaptive algorithm weights.

Antenna array communication using spreading codes

An improved base station which cancels the effects of known fixed interference sources produces a signal substantially free from the interference sources thereby increasing total channel capacity. The adaptive interference canceller base station includes a main antenna for receiving signals from other communication stations and at least one directional antenna directed toward an interference source. The main and directional antennas are coupled together such that an output signal substantially free from the interference is generated.

Adaptive cancellation of fixed interferers

A communication station includes an antenna system having multiple antennas and delay units for receiving a transmitted signal and outputting a combined signal having a known distortion imparted by the antenna system. The combined signal is in turn processed by a modem, which compensates for the known distortion in a manner which provides improved signal gain. The improved signal gain permits a reduction in transmit power and, accordingly, increased capacity of the communication station. Where the antenna system is to be remotely located from related signal processing equipment, separate units for the RF receiver/transmitter and the other signal processing equipment are provided so that the RF receiver/transmitter may also be remotely located along with the antenna system.

Communication station having an improved antenna system

A user equipment which receives a CDMA communication signal that is wirelessly transmitted includes a system for correcting phase errors in an information signal which has been transmitted. The correction system comprises circuitry for generating a correction signal and for combining the correction signal with the information signal to produce a corrected information signal. An analyzer analyzes the phase of the corrected information signal and generates an error signal based on the deviation of the analyzed phase from a reference phase. A bandwidth controller recursively adjusts the phase of the corrected information signal such that the phase of said corrected information signal is substantially equal to said reference phase. The bandwidth controller selects a bandwidth within an adjustable range based on the error signal, estimates an offset based on the error signal, and modifies the correction signal using the offset.

Continuously adjusted-bandwidth discrete-time phase-locked loop

A base station comprises a plurality of antennas. Each of the antennas is separated by a known distance. A first spread spectrum signal is transmitted having a first code. Using the plurality of antennas, a second spread spectrum signal is received having a second code. The second spread spectrum signal is time synchronized with the first spread spectrum signal. A distance determination is made based on in part a timing difference between the second code of the received second spread spectrum signal and the first code of the base station's transmitted first spread spectrum signal. A phase difference of a carrier signal of the second spread spectrum signal as received by each of the plurality of antennas is compared. An angle of the received second spread spectrum signal is determined using the known distance between the antennas and the phase difference. A location of a source of the second spread spectrum signal is determined using the determined angle and the distance determination.

Base station using an antenna array for location determination

A receiver and base station for producing phase-corrected channel signals. An adaptive matched filter produces a filtered signal by using a weighting signal. A rake receiver produces a filter weighting signal using a pseudo-noise signal generator. A channel despreader despreads the filtered signal using the pseudo-noise signal generated to produce a despread channel signal of the selected channel. A pilot channel despreader despreads the filtered signal using a pseudo-noise signal generator to produce a despread pilot signal of the pilot channel. A hard decision processor receives the despread channel signal of the selected channel and produces a correction signal. A phase-locked loop utilizes at least the despread pilot signal and produces a phase correction signal which is applied to produce phase-corrected channel signals.

Growing community of inventors

Huntington Station, NY, United States of America

David K Mesecher