Method of operating a message receiver
AssigneeMarconi Communications, Inc.
InventorsKhaled Fazel, Volker Hespelt, Volker Engels, Bernd Freidrichs
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Abstract
The invention relates to a method for the operation of a message receiver for a message, that is present as burst, which includes at least a training sequence and useful data, characterized in that the receiver is stepwise synchronized with the burst as the burst is received.
Claims27
Method for the operation of a message receiver for a message, that is present as a burst, which includes at least a training sequence and useful data, characterized in that the receiver is stepwise synchronized with the burst as the burst is received.
Method according to one of the preceding claims, characterized in that the receiver is synchronized during the second synchronizing stage with the carrier frequency of the burst.
Method according to one of the preceding claims, characterized in that the receiver is synchronized during the second synchronizing stage with the phase position of the carrier frequency.
Method according to one of the preceding claims, characterized in that the receiver is synchronized with the phase and/or the frequency of the carrier frequency tracking after the first synchronizing stage and/or during or after the second synchronizing stage.
Method according to one of the preceding claims, characterized in that tracking takes place when the message is decoded.
Method according to one of the preceding claims, characterized in that tracking and decoding take place by means of a Viterbi decoder and according to Viterbi & Viterbi algorithms.
Method according to one of the preceding claims, characterized in that the training sequence includes at least two partial sequences
Method according to one of the preceding claims, characterized in that at least one of the partial sequences is periodic.
Method according to one of the preceding claims, characterized in that at least one of the partial sequences includes a symbol sequence, which enables alignment of the time slot of the burst and calculation of the channel impulse response, the phase position, the gain control factor (AGC) as well as the transmission power.
Method according to one of the preceding claims, characterized in that one of the two partial sequences includes pilot signals.
Method according to one of the preceding claims, characterized in that one or both partial sequences includes at least pseudo noise sequences.
Method according to one of the preceding claims, characterized in that the useful data of the message is statistically evaluated for the second synchronizing stage.
Method according to one of the preceding claims, characterized in that the training sequence comprises a constant duration or number of symbols.
Method according to one of the preceding claims, characterized in that an incoming burst is detected in the receiver by means of power detection.
Method according to one of the preceding claims, characterized that the time slot structure is determined when the burst arrives.
Method according to one of the preceding claims, characterized in that the channel impulse response is calculated by cross correlation of the burst and the second partial sequence.
Method according to one of the preceding claims, characterized in that during cross correlation the training sequence is shifted by a pre-definable number of symbols, in order to determine the corresponding number of multipath propagation echoes.
Method according to one of the preceding claims, characterized in that the phase position and amplitude of each multipath propagation is determined from-the echoes.
Method according to one of the preceding claims, characterized in that the gain control factor is determined from each phase position and each amplitude.
Method according to one of the preceding claims, characterized in that the constant phase position is determined for each multipath propagation.
Method according to one of the preceding claims, characterized in that the periodic partial sequence is evaluated in the time domain.
Method according to one the preceding claims, characterized in that the other partial sequence is evaluated within the complex number range.
Method according to one of the preceding claims, characterized in that the training sequence is added as preamble to the useful data.
Dependencies are inferred from the claim text.