CDMA communication system and method

A communication method in a spread spectrum communication system for performing communication between a first station and second stations, comprising the steps of:

• transmitting, in each second station, a transmitting signal spread with a code Wi assigned to respective second stations, wherein the code Wi is selected from among a plurality of orthogonal codes which are orthogonal to each other;
• measuring, in said first station, a phase difference between a phase of code Wi of the transmitting signal transmitted from each second station and a reference phase of the code Wi for de-spreading the transmitting signal, and transmitting a phase difference information indicating the measured phase difference;
• and
• controlling, in each second station, a phase of the code Wi of the transmitting signal in accordance with the received phase difference information.

A communication method in a spread spectrum communication system for performing communication between a first station and second stations, comprising the steps of:

• transmitting, in each second station, a transmitting signal spread with a spreading code;
• performing, in said first station, a timing acquisition of the transmitting signal from each second station and transmitting a first phase difference information which indicates a phase difference between a phase of the spreading code of the transmitting signal and a reference phase of the spreading code for de-spreading the transmitting signal on the timing acquisition;
• setting, in each second station, the phase of the spreading code of the transmitting signal in accordance with the first phase difference information;
• performing, in said first station, a phase tracking of the transmitting signal from each second station and transmitting a second phase difference information which indicates a phase difference between a phase of the spreading code of the transmitting signal and a reference phase of the spreading code for de-spreading the transmitting signal during the phase tracking;
• adjusting, in each second station, the set phase of the spreading code of the transmitting signal in accordance with the second phase difference information.

A communication method in a spread spectrum communication system for performing communication between a first station and second stations, comprising the steps of:

• transmitting, in each second station, a transmitting signal spread with a spreading code which phase is slid by a predetermined amount;
• performing, in said first station, a timing acquisition of the transmitting signal from each second station and transmitting a first phase difference information which indicates a completion of the timing acquisition of the transmitting signal;
• setting, in each second station, the phase of the spreading code of the transmitting signal in accordance with the received timing of the first phase difference information;
• performing, in said first station, a phase tracking of the transmitting signal from each second station and transmitting a second phase difference information which indicates a phase difference between a phase of the spreading code of the transmitting signal and a reference phase of the spreading code for de-spreading the transmitting signal during the phase tracking;
• adjusting, in each second station, the set phase of the spreading code of the transmitting signal in accordance with the second phase difference information.

A code division multiple access communication system comprising a first station and a plurality of second stations, the first station providing a plurality of channels to each of forward and reverse links and a pair of forward and reverse channels being assigned to respective second stations, wherein:

• said first station includes demodulator which de-spreads a received signal on each reverse channel and measures a phase difference between a phase of a spreading code of the received signal and a reference phase of the spreading code for de-spreading the received signal;
• and
• said each second station includes a modulator which spreads a transmitting data with the spreading code whose phase is variable;
• wherein the spreading code is selected from among a plurality of orthogonal codes.

A second station for performing communication with a first station comprising:

• a spreading code generator which generates a spreading code assigned to said second station;
• and
• a modulator which spreads a transmitting data with the generated spreading code;
• wherein a phase of the spreading code for spreading the transmitting data in the modulator is variable.

A system for modulating an transmitting data in a spread spectrum communication system, comprising:

• an orthogonal code generator which generates an orthogonal code;
• a pseudo-noise (PN) code generator which generates a PN code;
• and
• a modulator which spreads the transmitting data with the generated orthogonal code and the generated PN code;
• wherein phases of generated orthogonal code and PN code are variable.

A communication method in a spread spectrum communication system for performing communication between a first station and second stations, comprising the steps of:

• transmitting a transmitting signal spread with a code Wi assigned to respective second stations, wherein the code Wi is selected from among a plurality of orthogonal codes which are orthogonal to each other;
• receiving a phase difference information indicating a phase difference between a phase of code Wi of the transmitting signal and a reference phase of the code Wi for de-spreading the transmitting signal;
• and
• controlling a phase of the code Wi of the transmitting signal in accordance with the received phase difference information.

A communication method in a spread spectrum communication system for performing communication between a first station and second stations, comprising the steps of:

• receiving a received signal transmitted from each second stations, wherein the received signal is spread with a code Wi assigned to respective second stations;
• measuring a phase difference between a phase of code Wi of the received signal and a reference phase of the code Wi for de-spreading the received signal;
• and
• transmitting a phase difference information indicating the measured phase difference,
• wherein the code Wi is selected from among a plurality of orthogonal codes which are orthogonal to each other.