Stanford Telecommunications, Inc.

Other

Hatch Graham, Iii

Leonard Schuchman

Ronald C Bruno

Charles Moses

Christine Nguyen

A portable cellular telephone system including a stationary transceiver for radio communication with a plurality of mobile transceivers within a geographic cell, a mobile transceiver within said geographic cell and having sufficient power to communicate with said stationary transceiver, and a portable transceiver of limited size for personal transport and use. The portable transceiver communicates with the mobile transceiver by spread spectrum techniques, and the mobile transceiver communicates with the stationary transceiver by frequency modulated radio transmission or by digital radio transmission.

Portable cellular telephone using spread spectrum communication with

In a Viterbi decoder including an add-compare-select (ACS) processor, speed is enhanced without loss of performance by maintaining a dynamic cumulative metric range for computed state metrics. Current state metrics are added to new branch metrics to obtain two computed metrics, and the smaller of the two computed metrics is stored along with previously computed state metrics. The stored state metrics are compared with a selected scale factor, for example one-half maximum scale factor, and all current state metrics are rescaled when the minimum stored metric value exceeds the selected scale factor.

Viterbi ACS unit with renormalization

A numerically controlled oscillator includes a phase accumulator which generates sequences of phase word phase signals. A demultiplexer 104 directs the odd and even numbered phase angle words of the sequence to identical but independent lookup tables to generate corresponding waveform signals. The wave form signals at the output of each lookup table occur at one-half the frequency of the system clock. A multiplexer 108 interleaves the output signals from the lookup tables to provide a properly ordered sequence of waveform signals at the frequency of the system clock. The maximum system clock frequency can be approximately twice the maximum operating frequency of each lookup table.

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Fremont, CA, United States of America

Hatch Graham, Iii