Interdigital Technology Corporation

Fryderyk Tyra

Louis J Guccione

Donald M Grieco

John W Haim

Leonid L Kazakevich

James D Nolan

Timothy A Axness

Robert T Regis

Fred M Schreider

An automatic gain control (AGC) method according to the present invention applies an initial gain by a digital AGC circuit in a timeslot is determined using a final calculated gain from the same timeslot in the previous frame together with an offset factor. An erase function is activated for a given data sample block when the number of saturated data samples that are detected within the block exceeds a threshold value. The power measurement made by the AGC circuit and used to update the gain is adjusted based on the number of measured data samples that are saturated. These elements provide a gain limiting function and allows limiting of the dynamic range for further signal processing.

Enhanced automatic gain control mechanism for time-slotted data transmissions

A received power of a code division multiple access (CDMA) signal is determined. Samples of a spectrum associated with the received CDMA signal are taken as received samples, which are then correlated with a code of the CDMA signal. For correlated samples below a first threshold, those correlated samples are processed by being made to be zero. For samples between the first threshold and a second threshold, those correlated samples are processed by rescaling. The correlated samples above the second threshold are passed unchanged. The received power level of the received CDMA signal is determined using the correlated samples after the processing.

Power measurement of received CDMA signals using soft threshold preprocessing after correlation

A communication system emulator digitally emulates a plurality of signal impairments created by the transmitter and receiver components and communication medium in a typical communication system, for use in evaluating and refining modem design. A variety of linear and non-linear distortion characteristics are impressed on baseband signals between modulators and demodulators to evaluate and refine modem performance without requiring transmission frequency components or communication channel. The emulator comprises transmit modules, receive modules and communication media modules, and can accept or output analog or digital signals. Each module is configurable to allow modeling of simplex or duplex communication, or a common base station with multiple users transmitting or receiving, all configurations with or without communication media impairment emulation. Each module can be configured to add a plurality of linear and non-linear impairments to a baseband signal.

Communication transmission impairment emulator

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Huntington Station, NY, United States of America

Fryderyk Tyra