초록 ▼

An improved spread spectrum communication system includes a transmitter and a receiver utilizing a pilot channel for the transmission of pure rather than modulated PN codes for code acquisition or tracking purposes with a lower bit error rate. The pilot signal is used to obtain initial system synchr

An improved spread spectrum communication system includes a transmitter and a receiver utilizing a pilot channel for the transmission of pure rather than modulated PN codes for code acquisition or tracking purposes with a lower bit error rate. The pilot signal is used to obtain initial system synchronization and phase tracking of the transmitted spread spectrum signal. At the transmitter side, a Walsh code generator, a Walsh modulator, a first PN code generator, a first band spreader, a second band spreader, finite impulse response filters, digital-analog converters, low-pass filters, an intermediate frequency mixer, a carrier mixer, a band-pass filter are used to transmit a spread spectrum signal. At the receiver side, a corresponding band-pass filter, a carrier mixer, an intermediate-frequency mixer, low-pass filters, analog-digital converters, a second PN code generator, an I channel despreader, a Q channel despreader, a PN code synchronization controller, a Walsh code generator, a first Walsh demodulator, a second Walsh demodulator, accumulator & dump circuits, a combiner, and a data decider are used to demodulate a received spread spectrum signal

대표청구항 ▼

[ What is claimed is:] [1.] A spread spectrum communication system, comprising:a pilot channel signal generator for generating a pilot signal exhibiting a predetermined binary value;a pseudo-random noise generator for generating first and second pseudo-random noise codes in response to a pseudo-rand

[ What is claimed is:] [1.] A spread spectrum communication system, comprising:a pilot channel signal generator for generating a pilot signal exhibiting a predetermined binary value;a pseudo-random noise generator for generating first and second pseudo-random noise codes in response to a pseudo-random noise clock;first Walsh code generator means for generating a first Walsh code according to a first set of Walsh functions, and generating a second Walsh code according to a second set of Walsh functions;modulator means coupled to receive an input information signal and the pilot signal, for modulating the pilot signal according to the first Walsh code and modulating the input information signal according to the second Walsh code to generate a modulated pilot signal and a modulated information signal, respectively; andspreader means for band spreading the modulated pilot signal and the modulated information signal with each of the first and second pseudo-random noise codes to generate a spread spectrum signal to be transmitted via a communication channel.