Motorola Corporation

Lucent Technologies Inc.

Abdulkadir Dinc

Krishna Balachandran

Kiran Meghashyam Rege

Kirk K Chang

Frederic Fontaine

Yogendra Champaklal Shah

Aparna Khurjekar

Zhendong Cao

David Zaff

Theodore G Lubbe

Eoin M Buckley

Haim Teicher

A method of terminating iteration calculations in the decoding of a received convolutionally coded signal includes a first step of providing a turbo decoder with a first and second recursion processors connected in an iterative loop. Each processor has an associated extrinsic input and output. A next step includes cross-correlating the input and output of at least one of the processors to provide a cross-correlation value at each iteration. A next step includes terminating the iterations when the measure of the cross-correlation value index exceeds a predetermined threshold.

Iteration terminating using quality index criteria of turbo codes

A spread spectrum communications CDMA system ( ) in which power control mitigates received signal fluctuations due to Rayleigh fading and hence achieve optimal system ( ) capacity. The method and hardware implementation ( ) is described for the inner loop ( ) fast forward power control algorithm for a CDMA2000 handset. Good performance shown with the simulation results and a simple Application Specific Integrated Circuit (ASIC) implementation is achieved with a method and an apparatus ( ) for the implementation of Eb/Nt estimation for inner loop ( ) forward power control in CDMA2000 mobile station. The IS-95A system ( ) employs a slow power control scheme for the Forward link ( ). In the CDMA2000 system ( ), a power control subchannel is introduced for a faster forward power control mechanism.

Method and an apparatus for Eb/Nt estimation for forward power control in spread spectrum communications systems

Demodulator assignment logic is provided that confirms the presence and quality of a multipath before assigning a parallel demodulator to that multipath. Multipath presence and quality are confirmed when at least two power measurements of a multipath at least equal a selectable power threshold. Before permitting demodulated data from an assigned demodulator to be processed, demodulator assignment logic further reconfirms the presence and quality of a multipath via another more reliable power measurement that at least equals another selectable power threshold.

Apparatus and methods for improving the assignment of parallel demodulators to multipaths of wireless signals

A spread spectrum communications system where power control mitigates received signal fluctuations. An implementation is described for forward power control wherein received data is checked for errors. Where an error is detected energy levels of the power control bits and traffic bits are determined. The energy level of the power control bits is compared against a first predetermined threshold wherein if the energy level of the power control bits is less than the first predetermined threshold an increased in forward power is requested. Otherwise, the energy level of the traffic bits are compared against a second predetermined threshold wherein if the energy level of the traffic bits is less than the second predetermined threshold a decrease in forward power is requested. Otherwise an increase is requested.

Forward power control determination in spread spectrum communications systems

A method for improved decoding of received convolutionally coded input data uses data scaling to provide near ideal turbo decoding. The method includes a first step of loading a portion of the input data into a buffer. A next step includes calculating a mean of the data in the portion of the input data. A next step includes computing a root-mean-square value of the portion of the input data using the mean from the calculating step. A next step includes deriving a scaling factor from the root-mean-square value of the computing step, and a next step includes scaling the portion of input data by the scaling factor of the deriving step.

Decoding of turbo codes using data scaling

A transceiver system having a base unit and a handset for communicating over a number of communication channels that are automatically switched during talk-time. A received-signal-strength-indicator (RSSI) circuit connects to the receiver for measuring the average energy received by the receiver over a baseband frequency bandwidth. The average energy includes the information, interference and noise portions of the received energy. The RSSI circuit transmits an RSSI output when the average energy exceeds a predetermined RSSI threshold. A discriminator-interference-and-noise-energy (DINE) circuit connects to the receiver for measuring out-of-band energy received by the receiver which is above the baseband frequency bandwidth. The out-of-band energy primarily comprises interference and noise energy. The DINE threshold detector provides a DINE output when the out-of-band energy exceeds a predetermined DINE threshold. A microcontroller connects to the RSSI and DINE circuits for monitoring, in real time, the RSSI and DINE outputs to detect the appearance of an interferer on the currently used communication channel. When an interferer is detected, the carrier frequency is automatically switched to a clean communication channel.

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Jersey City, NJ, United States of America

Abdulkadir Dinc