US 2003/0198286 A1 · Signal detection in a direct-sequence spread spectrum transmission system

Abstract

A receiver (10) achieves more reliable detection of signals transmitted by Direct Sequence Spread Spectrum Transmission by correlating received signals with a separate of N symbol patterns via N detector stages (181-18N). A maximum peak power detecting mechanism (241-24N, 261-26N and 28) detects which of the N correlated symbol patterns has a maximum peak power, as well as the identity of each of the N patterns actually received and an index of the peak power in each symbol. A computing mechanism (30, 32 and 34) computes a running power average of the received signals, while a ratio computing stage (26) computes the ratio of the largest peak power of the N correlated symbol patterns to the running power average. A comparator stage (38 and 40) compares the ratio to a threshold value to determine a first symbol in the received pattern. From knowledge of the first symbol received, the identity of that symbol, and the true burst location of the received symbol relative to a receiver time base can be determined, thus providing more reliable signal detection.

Claims9

Dependent claims

A method for improved detection of received signals transmitted by Direct Sequence Spread Spectrum Transmission, comprising the steps of:

continuously correlating the received signals with each of N known symbol patterns;
determining which of the N correlated symbol patterns has a largest peak power;
determining a running power average of the received signals;
computing a ratio of the largest peak power of the N correlated symbol patterns to the running power average;
and
comparing the ratio to a threshold value to determine a first symbol in the received pattern, an identity of the first symbol, and a true burst location relative to a receiver time base.

3 more elements

Apparatus for improved detection of signals transmitted by Direct Sequence Spread Spectrum Transmission, comprising:

N detector stages, each correlating received signals with a separate one of N separate known symbol sequences;
a maximum peak power detecting mechanism for:
(a) detecting which of the N correlated symbol patterns output by the N detector stages has a maximum peak power, (b) determining an identity of each of the N symbol patterns actually received and (c) establishing an index of the peak power within the symbol in each received symbol pattern;
a first computing mechanism for computing a running power average of the received signals;
a second computing mechanism for computing a ratio of the peak maximum power, as established by the maximum peak power detecting mechanism, to the running power average;
as established by first computing mechanism, and
a comparator stage for comparing the ratio to a threshold value to determine a first symbol in the received pattern, the first symbol having an identity corresponding to the one of the N correlated symbol patterns having the largest peak power, and the first symbol having a true burst location relative to a receiver time base corresponding to an index of the peak power within that symbol.

4 more elements

Dependencies are inferred from the claim text.

Signal detection in a direct-sequence spread spectrum transmission system

Life of this patent

Signal detection in a direct-sequence spread spectrum transmission system

Life of this patent

Abstract

Claims9