Interdigital Technology Corporation

Bae Systems Information and Electronic Systems Integration Inc.

Intel Corporation

Bae Systems Information and Electronics Systems Integration Inc.

Interdigital Communications Corporation

Gary R Lomp

Fatih M Ozluturk

John Michael Kowalski

Avi Silverberg

Donald L Schilling

John W Haim

Alexander M Jacques

David K Mesecher

Jeffrey S Polan

Michael J Luddy

Robert T Regis

Alexander Marra

Faith M Ozluturk

Leonid L Kazakevich

Matthew J Sherman

Joseph Garodnick

David A Haessig, Jr

Timothy F Moore, Iii

Fatih Ozukturk

Leonid Kazarkevich

Charles Robert Giardina

Barnet M Schmidt

Joel D Reiss

Gilbert E La Vean

John F Courtien

Andrew M Comba

Leonid Kazerkevich

Lee M Garth

Michael Luddy

Robert E Regis

A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

Automatic power control system for a code division multiple access (CDMA) communications system

A system and method for optimally combining multi-path signals is presented. A first signal is received that traveled a first path from a transmitter to a receiving location and a second signal is received that traveled a different second path from the transmitter to the same receiving location. The paths are different so that the first and second signals contain the same signal data but the first signal has a first distortion that is different than a second distortion in the second signal. According to an objective function, the method adaptively generates a first weight value and a second weight value. The first and second weight values are applied to the respective first and second signals to produce respective first and second weighted signals. The first and second weighted signals are linearly combined producing a combined signal with a combined signal degradation.

System and algorithm for multipath mitigation

A system and method for generating a low probability of detection (LPD) waveform is presented. The method modulates pre-modulated symbols using pulse-position modulation (PPM) to produce PPM modulated signals with a modulated in-phase (I) component and a modulated quadrature (Q) component. Next, frequency hopping is used to transmit the modulated I component at a randomized start time within a time slot and to transmit the modulated Q component at the randomized start time within the same slot. The modulated Q component does not overlap with the modulated I component. The method can also overlay transmission security (TRANSEC) pseudorandom (PN) overlay on the modulated Q component and the modulated I component before the modulated Q component and the modulated I component are transmitted.

Low probability of detection (LPD) waveform

A spread signal is produced having an adjustable spread spectrum. A data signal is provided for transmission. The data signal is processed to have a first spread spectrum. The processed first spread spectrum data signal is filtered to have one out of a plurality of spread spectrums. The filtering capable of producing a signal having a spread spectrum of any of the plurality of spread spectrums. The filtered one spread spectrum data signal is transmitted.

Setting a transmission power level for a mobile unit

A subscriber unit for use in a multiple access spread-spectrum communication system includes a spread spectrum radio interface, responsive to a rate function signal from a base station, and first and second despreaders. The base station assigns the rate function spread-spectrum message channels and the first despreader recovers and modifies an information signal one of the spread spectrum message channels. The information channel mode is then modified for processing by the second despreader, with the second despreader supporting a different information signal rate. The subscriber unit has a capability of communicating with a dynamically changing a transmission rate of an information signal which includes multiple spread spectrum message channels. The system includes a closed loop power control system for maintaining a minimum system transmit power level for a radio carrier station and the subscriber units, and system capacity management for maintaining a maximum number of active subscriber units for improved system performance.

Code division multiple access (CDMA) communication system

A system and method for calculating a time of arrival (TOA) of an electromagnetic signal is presented. A method receives a fast Fourier transform (FFT) signal that is a FFT of an original electromagnetic signal containing symbol data. The FFT signal is either multiplied or divided with a value to remove the symbol data. Removing the symbol data generates a perturbed data values representing perturbed signal with a perturbed covariance. The method calculates a perturbed covariance of the perturbed data values. After the perturbed covariance is calculated, the method at least partially corrects the perturbed covariance to produce a corrected covariance. The TOA of the original electromagnetic signal is calculated based, at least in part, on the perturbed covariance.

Method and apparatus for waveform independent ranging

A desired signal modulated with N symbols is detected in the presence of a constant modulus (CM) interferer that produces M symbols. Observation samples corresponding to the desired signal and the interferer are obtained from a signal recovery stage. N observation constellations are defined, each having M constellation points corresponding to the symbols produced by the interferer, and the points form a circular perimeter of the constellation with a radius corresponding to the strength of the interferer. The perimeter of each constellation is centered on one of N defined symbol points representing the different possible symbols of the desired signal. Distances between the observation samples and the circular perimeter of each observation constellation are determined. For each observation sample, the symbol point on which the constellation perimeter closest to the sample is centered, is selected as a symbol of the desired signal.

Geometric detector for communicating through constant modulus (CM) interferers

A base station for controlling transmission power during the establishment of a communication channel utilizes the reception of a short code during initial power ramp-up. The short code is a sequence for detection by the base station which has a much shorter period than a conventional access code. The ramp-up starts from a power level that is lower than the required power level for detection by the base station. The power of the short code is quickly increased until the signal is detected by the base station. Once the base station detects the short code, it transmits an indication that the short code has been detected.

Method and apparatus for performing an access procedure

A wireless code division multiple access (CDMA) communication system, including a base station (BS) and a subscriber unit (SU), uses adaptive forward power control (AFPC) and adaptive reverse power control (ARPC) to control the transmit power of forward and reverse link radio frequency (RF) channel signals, respectively. Automatic gain control (AGC) signals are produced to maintain the level of forward and reverse CDMA signals at a near constant level. The CDMA signals are despread to produce first and second despread signals. The first and second despread signals are used to produce a first error signal e. A second error signal eis produced based on the AGC signals. Combined error signals are formed based on the first error signal eand the second error signal e. The combined error signals are hard limited to form adaptive power control (APC) bits used to control the level of the forward and reverse link RF channel signals.

Adaptive forward power control and adaptive reverse power control for spread-spectrum communications

Subscriber unit for performing an access procedure

A wireless communication unit comprises circuitry configured to receive a voice data associated with a first logical channel. The circuitry further configured to receive a non-voice data associated with a second logical channel. The voice data and non-voice data carried by a wireless channel set during a time period. The wireless channel set comprises a plurality of wireless channels. The wireless channel is associated with a subscriber unit. Circuitry is configured to insert information into the non-voice data, when the non-voice data is missing in the wireless channel set during the time period.

Transferring voice and non-voice data

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Centerport, NY, United States of America

Gary R Lomp