Motorola Corporation

John William Arens

Christopher N Kurby

Bradley B Bakke

James P Phillips

Stanley W Attwood

Dariusz Andrzej Blasiak

Kathleen Helen Ryan

A Corbett Kull

Jerrold Lee Grubb

A time-framed communications transceiver maintains synchronization through fade conditions by resetting a counter (640) whenever new synchronization parameters are stored in a memory (630) based on bursts detected by a receiver (610) and a burst synchronizer (620). A transmitter (690) transmits bursts based upon the synchronization parameters in the memory (630) when the time counter (640) has not exceeded a predetermined period of time. The receiver (610) re-establishes the synchronization parameters in the memory (630) when the time counter exceeds another, longer predetermined period of time before transmission by the transmitter (690).

Transceiver and associated method for surviving fades

In a method and apparatus for maintaining a minimum transmission power level between two communication stations, each station measures the other's received signal quality, and returns an indication of signal quality as part of a regular maintenance burst. Each station adjusts its own transmission power level based on the returned signal quality indication. The signal quality indication is based on the received ratio of bit energy to total noise power spectral density which is calculated from an estimated bit-error-rate.

Method and apparatus for bi-directional power control in a digital

A decoding apparatus (200) decodes a coherent, differentially encoded multi-level phase shift keying (DEPSK) modulated signal. A coherent receiver (101) receives and, subsequently, outputs the coherent DEPSK modulated signal to a metric computer (201). The metric computer (201) generates a soft decision metric .LAMBDA.(s(n)) corresponding to the coherent DEPSK modulated signal which is outputted to a forward error correction (FEC) decoder (107). The FEC decoder (107) decodes the coherent DEPSK modulated signal in accordance with the soft derision metric .LAMBDA.(s(n)) corresponding to the coherent DEPSK modulated signal.

Soft decision digital communication method and apparatus

A burst detector (140) detects the occurrence of a burst in a signal receiver. A filter (220) having an impulse response characteristic of an expected burst filters a received signal. A subtractor (230) subtracts a filtered version of the received signal from a delayed and filtered version of the received signal to provide a detection signal. A burst edge detector (250) detects a leading edge of the burst based on the detection signal.

Method and apparatus for burst detecting

An earth station transceiver (210) is provided for communicating with at least one satellite (110, 120) in orbit. The earth station transceiver (210) has an antenna with an array of antenna elements (220, 230) and steering circuitry (240) for steering an antenna pattern created by the array of antenna elements. A position of a beam (310-330) from a satellite can be represented by a beam number. The antenna pattern can be determined without taking signal quality measurements when the beam is at an extreme elevation angle as represented by the beam number. Signal quality measurements can alternatively be made during a time slot or frame to choose an antenna pattern instead of choosing an antenna pattern based on satellite beam number when the beam is not at an extreme elevation angle. Signal quality measurements using the same antenna pattern are made to perform an intra-site handoff. Signal quality measurements using all antenna patterns are made to perform an intersite handoff.

Transceiver having steerable antenna and associated method

The present invention provides an apparatus for symbol clock recovery from a received signal having wide range of frequency errors or offsets. Magnitudes of received inphase and quadrature sampled signals are determined (210). These magnitudes are summed and distributed (227) into accumulator registers (231, 232, 233, 235, 237, 239) for accumulating sums of the first and second signals for each sample time and substantially over a length of an expected burst. A maximum-minimum determination circuit (240) chooses the sample time having a largest or smallest sum to provide a recovered clock signal (270). The carrier could then be recovered (260), and a downsampler (250) downsamples the received inphase and quadrature signals based on the recovered clock signal.

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Grayslake, IL, United States of America

John William Arens