Patent ID: 6625204
Filing Date: 2003-09-23
Classification: H04B

Abstract:
A receiver packet detector apparatus for single spreading sequence spread bit packet signal transmissions having in-phase and quadrature components, comprising a received signal input line, a QAM modulator connected to the input line, the QAM modulator further comprising a splitter connected to the input line for separating received signals into first and second paired inputs, first and second multipliers connected to the first and second paired inputs, a numerically controlled oscillator connected to the first multiplier, a 90Â° phase shifter connected to the numerically controlled oscillator and connected to the second multiplier, first and second output lines connected to the first and second multipliers, first and second low pass filters connected to the first and second output lines for removing high frequencies from the output lines, first and second low frequency signal lines connected to outputs of the first and second low pass filters, first and second identical despreading filters connected to the first and second low frequency signal lines, first and second despread signal lines connected to outputs of the first and second despreading filters, and first and second pairs of synchronization matched filters connected to the first and second despread signal lines for producing packet synchronization sequence outputs.