Interdigital Technology Corporation

Hughes Aircraft Company

Other

Hughes Electronics Corporation

International Mobile Machines Corporation

Inertdigital Corporation

John D Kaewell

David M Cooley

Mark A Lemmo

Michael W Regensburg

David Vessal

Scott David Kurtz

Joseph J DiGiovanni

Eric Johns

Joseph Mark Smith

Youngky Kim

Kevin Kinney

Jim J Huah

William T Vanderslice, Jr

Nicholas C Schreier

James J Roller

Jim J Huan

Walter Estulin

A CDMA communication system includes a signal processor which encodes voice and nonvoice signals into data at various rates, e.g. data rates of 8 kbps, 16 kbps, 32 kbps, or 64 kbps as I and Q signals. The signal processor selects a specific data rate depending upon the type of signal, or in response to a set data rate. When the signal is received and demodulated, the baseband signal is at the chip level. Both the I and Q components of the signal are despread using the conjugate of the pn sequence used during spreading, returning the signal to the symbol level. Carrier offset correction is performed at the symbol level. A lower overall processing speed is therefore required.

Pre-phase error correction

Pre-phase error correction transmitter

In a system having a received PN clock signal, a method is disclosed for providing a synchronized system clock signal having reduced jitter wherein the synchronized system clock signal is synchronized with the received PN clock signal. The method includes providing a stable high frequency reference signal and dividing the high frequency reference signal to provide a system clock signal having a plurality of system clock phases. The method also includes adjustably selecting a system clock phase of the plurality of system clock phases in accordance with the received PN signal in order to provide the synchronized system clock signal. The received PN clock signal is recovered by providing PN phase adjustments of the received PN clock signal. A tracking control signal is provided in accordance with the PN phase adjustments and the system clock phase is adjustably selected in accordance with the tracking control signal. The high frequency reference signal can be multiplied prior to the dividing.

Synchronizing PCM and pseudorandom clocks

A subscriber cluster unit for a wireless telecommunication system provides a wireless interface with a base station for a plurality of subscriber units. The cluster unit has a plurality of frequency agile modems for processing wireless communications with the base station and a plurality of subscriber line circuits, each for providing a telecommunication connection with a subscriber unit. A control processor assigns a modem for each communication between the base station and a selected subscriber unit which is coupled to one of the line circuits and associates that line circuit with the assigned modem for that communication. Thus, a subscriber unit coupled with any of the line circuits can communicate with the base station via any of the modems.

Modularly clustered radiotelephone system

A wireless transmitter comprises an input configured to receive a data signal. A mixer mixes the data signal with a correction signal producing a corrected signal. The correction signal changes a phase in the data signal to compensate for a measured phase error at a desired receiver. A modulator modulates the corrected signal to radio frequency as a radio frequency signal. An antenna radiates the radio frequency signal.

A digital spread spectrum communication system calculates phase and frequency error on a received signal from a communicating entity during a wireless communication and pre-corrects a signal for phase and frequency error prior to transmission to that entity.

CDMA system which uses pre-rotation before transmission

Subscriber terminal temperature regulation

The present invention is an apparatus for reducing transmission errors by a user equipment (UE) when transmitting a communication signal. An RF communication signal is received at the UE and analyzed for errors. A correction signal is then generated based upon the analysis. Prior to transmission of the communication signal from the UE, the communication signal is corrected using the correction signal.

User equipment which uses pre-rotation before transmission

The present invention is a method and apparatus for reducing transmission errors by a user equipment (UE) when transmitting a communication signal. An RF communication signal is received at the UE and analyzed for errors. A correction signal is then generated based upon the analysis. Prior to transmission of the communication signal from the UE, the communication signal is corrected using the correction signal.

The present invention is a method and apparatus for reducing transmission errors by a base station when transmitting a communication signal. An RF communication signal is received at the base station and analyzed for errors. A correction signal is then generated based upon the analysis. Prior to transmission of the communication signal from the base station, the communication signal is corrected using the correction signal.

Base station which uses pre-rotation before transmission

The present invention is an apparatus for reducing transmission errors by a base station when transmitting a communication signal. An RF communication signal is received at the base station and analyzed for errors. A correction signal is then generated based upon the analysis. Prior to transmission of the communication signal from the base station, the communication signal is corrected using the correction signal.

A power-conserving time division multiple access (TDMA) radio telephone system is disclosed in which a cluster of subscriber stations, remote from a base station, employs a common pool of frequency-agile modems each of-which digitally synthesizes, on a timeSlot-by-timeSlot basis, the different channel-identifying intermediate frequencies needed to support communications between several of the subscriber stations and the base station. Power conservation is facilitated inter alia by controlling the assignment of modems to calls, maintaining unassigned modems in a powered-down state and by controlling the number of calls using the same time slot. Delay in assigning a powered-down modem to a call is eliminated by making available to all modems the highest quality synchronization information obtained by any of the active modems.

Growing community of inventors

Bensalem, PA, United States of America

John D Kaewell