Motorola Corporation

Kevin M Laird

Danny T Pinckley

Paul Fielding Smith

Yuda Yehuda Luz

Alan P Rottinghaus

John M Smith

Daniel Morris Lurey

Robert C Elder

Donald E Bailey

James M O'Connor

Tony Kobrinetz

Shelia Marie Rader

Shay-Ping T Wang

Bernard Eugene Sigmon

ShaoWei Wei Pan

Stephen Chih-Hung Ma

Steven T Barrett

Richard E Murray

Robert Mark Harrison

Paul D Marko

Craig P Wadin

Gregory L Cannon

Jack Anthony Smith

Eric R Schorman

Jiangnan Jason Chen

Mansoor Ahmed

Walter J Rozanski, Jr

Kamyar Rohani

Charles N Lynk

Nicholas William Whinnett

Sybren Daniel Smith

Anthony Kobrinetz

David Myara

Jeffrey G Toler

Sheila M Rader

Soodesh Buljore

Leo G Dehner, Jr

Frank Fei Zhou

Walt Rozanski

John W Battin

A method and apparatus for long code generation in synchronous, multi-chip rate systems, wherein a first code sequence having a first bit rate, and a second code sequence having the first bit rate, the second code sequence being a time delay of the first code sequence, are multiplexed together, producing a desired long code.

Method and apparatus for long code generation in synchronous, multi-chip rate systems

A method of selecting an ARQ method for retransmitting a data frame based on an accumulated signal to noise ratio (SNR) of systematic bits in the data frame at a receiving unit The sending unit tracks the accumulated SNR of systematic bits by using channel SNR measurement reports sent by the receiving unit The method utilizes Chase combining of re-transmitted systematic bits (via Partial incremental redundancy transmissions) until the accumulated SNR of the systematic bits has reached a suitable value, and then switches to sending only parity bits (via Full incremental redundancy) in retransmissions. In addition, the method alters the allocation of resources, such as code power, to provide only that necessary for successful decoding of the transmitted frame. The sending unit informs the receiving unit of the type of transmission, number of the transmission and/or resource allocation associated with the data frame.

Apparatus and method for dynamically selecting an ARQ method

A transmitter uses adaptive array weights to modify a gain and a phase of a communication signal to produce a plurality of element communication signals coupled to antenna elements in an adaptive array antenna. The communication signal is transmitted along with an element pilot signal that is coupled to one of the elements in the adaptive array antenna. In a receiver, the communication signal is received, and the element pilot signal is received. Thereafter, the adaptive array weights used at the transmitter are estimated in response to comparing characteristics of the received element pilot signal to characteristics of the received communication signal.

Method and system for estimating adaptive array weights used to transmit a signal to a receiver in a wireless communication system

In a wireless communication system, a chip time is selected in a complex pseudonoise (PN) sequence generator. For a next chip time following the selected chip time, a phase difference between a previous complex PN chip and a next complex PN chip is restricted to a preselected phase angle. In one embodiment, every other chip time is selected and the preselected angle is 90 degrees.

Method and system for generating a complex pseudonoise sequence for processing a code division multiple access signal

In a digital preprocessing system for processing a digital signal for analog transmission, the digital signal is up-sampled to produce a digital up-sampled signal having signal components in a plurality of Nyquist bands including a first Nyquist band and a plurality of super-Nyquist bands at higher frequencies than the first Nyquist band, wherein the first Nyquist band includes a baseband signal component and a plurality of aliased signal components. Thereafter, one of the plurality of signal components in the first Nyquist band is selected from the digital up-sampled signal. Finally, the selected one of the plurality of signal components is output at a frequency that will cause a digital to analog converter to output an aliased signal component in a super-Nyquist band nearer an anticipated peak amplitude of a filtering characteristic of the digital to analog converter than an aliased signal component in the super-Nyquist band that would be output by the digital to analog converter processing the baseband signal component.

Method and apparatus for processing a digital signal for analog transmission

Multiple access digital transmitter and receiver

A peak-reducing waveform is estimated and summed with a composite signal to reduce the peak-to-average power ratio of the composite signal. The estimate of the peak-reducing waveform is modified to have Walsh code components orthogonal to the assigned Walsh codes. An iterative process of estimating subsequent peak-reducing waveform is implemented to produce a peak-reducing waveform which, when summed with the composite signal, results in a composite signal having a peak-to-average ratio at a desired level and thus does not have the effects of remodulating the assigned Walsh codes. Constraints on the magnitude of the unassigned Walsh code components can be included for controlling the power level under the unassigned Walsh codes.

Method and apparatus for reducing peak-to-average power ratio of a

An apparatus that includes a logarithm based processor (216) having at least one digital logarithm converter (202) and a power amplifier (208) responsive to the logarithm based processor (216).

Apparatus using a logarithm based processor

An apparatus for amplifying a signal that includes a digital processor (12) producing a first digital signal (20) and a second digital signal (22), a pulse width modulator (32) receiving the first digital signal (20) and producing a pulse width modulated signal, an amplitude restoration module (37) responsive to the pulse width modulator (32), the amplitude restoration module (37) producing an amplitude envelope signal, a frequency upconverter (16) receiving the second digital signal (22) and producing a frequency modulated signal, and a power amplifier (18) responsive to the frequency upconverter and the amplitude restoration module (37). The power amplifier receives the frequency modulated signal and the amplitude envelope signal and produces an amplified output signal.

Apparatus for amplifying a signal using a digital processor

A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Multi-channel digital transceiver and method

A method and apparatus for mitigating error in a received communications signal includes an error mitigator (35) of a communication unit (12) which receives and performs mitigation based on an error indication. In a first embodiment the error indication is a phase or non-used data symbol indicating error in ADPCM data, and mitigation includes changing certain nibble values to different predetermined values. In a second embodiment the error indication may include other parameters, e.g., a CRC frame error indicator, and an error estimator (34) determines a level of corruption in the ADPCM data. The error mitigator (35) applies a predetermined set of replacement values based on the indicated level of corruption and the mitigated data is subsequently decoded in an ADPCM decoder (26).

Method and apparatus for error mitigating a received communication signal

A digital radiotelephone system employs vocoders to convert between analog speech and a digital format suitable for transmission via radio. Under most circumstances, the highest data rate is selected for optimum audio quality. When the system occupancy exceeds a particular threshold, as detected at the fixed site of the system, some or all of the vocoders are instructed to switch to a lower data rate to provide for an increase in the number of communication channels. Further, a portable subscriber unit may autonomously change its vocoder data rate depending upon the charge state of its battery.

Apparatus and method for adapting a digital radiotelephone system to

An information gap in an ADPCM signal is detected in one or both of a transmitter or receiver. This detection can be accomplished using a voice activity detector. When an information gap is detected, a clock signal to the encoder and/or decoder is interrupted. Alternatively, null frames can be inserted into the encoder and/or decoder. When null frames are used, it is preferable to insert comfort noise into the signal output from the decoder.

Method and apparatus for maintaining convergence within an ADPCM

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Haltom City, TX, United States of America

Kevin M Laird