US 5,400,359 A · Spread spectrum communication system and an apparatus for communication utilizing this system

Abstract

The present invention relates to a spread spectrum communication system in which a PN code p(t) is generated from a PN generator, data d(t) is multiplied by the PN code p(t) by a multiplier, and multiplied output is subjected to BPSK modulation by a BPSK modulating block. The PN code p(t) is subjected to BPSK modulation at BPSK modulating block, the result is delayed by at least 1 chip of the PN code by a delay block, combined with a modulated signal from BPSK modulating block, converted to an RF signal, and then it is transmitted from an antenna. The signal received by an antenna is amplified by RF amplifier block, converted to an intermediate frequency signal by frequency converting block, split into two, one of the split signals is directly applied to a multiplier, the other is delayed by a delay block, and then these two split signals are multiplied by a multiplier and thus data d(t) is demodulated and output.

Claims36

Dependent claims

In a spread spectrum communication system, a method comprising the steps of:

transmitting, in combination, a first signal modulated by a PN code and data and a second signal modulated only by said PN code and thereafter delayed with respect to said first signal by a time period corresponding to at least one chip of said PN code;
receiving and splitting into third and fourth signals said transmitted signals;
delaying by said time period one of the third and fourth signals;
and
multiplying the delayed one of the third and fourth signals by the other to demodulate the data by despreading.

2 more elements

An apparatus for communication employing a spread spectrum communication system, comprising:

a transmitter for transmitting, in combination, a first signal modulated by a PN code and data and a second signal modulated only by said PN code and thereafter delayed with respect to said first signal by a time period corresponding to at least one chip of said PN code;
a receiver for splitting a received signal into third and fourth signals, delaying one of the third and fourth signals by said time period, and multiplying the delayed one of the third and fourth signals with the other to despread and demodulate the data.

An apparatus for communication transmitting binary digital data employing spread spectrum communication system, comprising:

a transmitter for generating a first modulated signal modulated by said binary digital data and by a first PN code and a second modulated signal modulated by a second PN code having the same chip rate and the same code length but different sequence from said first PN code for transmitting said first and second modulated signals in combination;
and
a receiver receiving and splitting into two said transmitted signal, filtering one of the split signals corresponding to said first PN code, filtering the other one of said split signals corresponding to said second PN code and for multiplying respective filtered outputs to demodulate said binary digital data.

An apparatus for transmitting data in a spread spectrum communication system employing frequency hopping, comprising:

a transmitter including:
a multiplier for multiplying a PN code with a multibit data signal to provide a spread data signal;
a carrier generator for generating a frequency hopping (FH) carrier signal having a frequency that changes every preset number of data bits;
a first modulator for modulating the FH carrier signal with the PN code and delaying the modulated signal by an arbitrary time delay longer than a time duration between carrier frequency changes;
a second modulator for modulating the spread data signal with the FH carrier signal;
a combiner for combining and transmitting the signals from the first and second modulators;
a receiver including:
means for receiving the transmitted signals and splitting into two the received signal;
a delay for delaying one of the split signals by the preset delay;
and
means for despreading the delayed signal and the other one of the split signals to demodulate the multi-bit data data.

8 more elements

Dependencies are inferred from the claim text.

Spread spectrum communication system and an apparatus for communication utilizing this system

Life of this patent

Spread spectrum communication system and an apparatus for communication utilizing this system

Life of this patent

Abstract

Claims36