Spread spectrum communication system and its transmitter and receiver

In a spread communication system having a transmitter and a receiver and communicating by a spread spectrum communication method between said transmitter and said receiver, said transmitter comprising:

• means for producing a first type of spread code and a second type of spread code;
• selection means connected to said means for producing for continually selecting between said first type of spread code and said second type of spread code mm according to a predetermined transmission pattern;
• and
• transmitting means for transmitting said first type of spread code and said second type of spread code from said selection means as a synchronizing signal in accordance with said predetermined transmission pattern, wherein
• said transmitting means includes means for transmitting said first type of spread code and said second type of spread code a total of (2.sup.N +N-2) times at a maximum in accordance with an M sequence code of degree N used as said predetermined transmission pattern.

In a spread communication system having a transmitter and a receiver and communicating by a spread spectrum communication method between said transmitter and said receiver, said transmitter comprising:

• means for producing a first type of spread code and a second type of spread code;
• selection means connected to said means for producing for continually selecting between said first type of spread code and said second type of spread code according to a predetermined transmission pattern;
• and
• transmitting means for transmitting said first type of spread code and said second type of spread code from said selection means as a synchronizing signal in accordance with said predetermined transmission pattern, wherein
• said transmitting means include means for adding and inserting a code having a value that is equal to "0" into an M sequence code of degree N having a sequence of "0" for (N-1) times and is used as said predetermined transmission pattern, and means for transmitting said first type of spread code and said second type of spread code a total of (2.sup.N +N-1) times at a maximum in accordance with said code having a value that is equal to "0" added and inserted into said M sequence code.

In a spread spectrum communication system having a transmitter and a receiver communicating by a spread spectrum communication method said transmitter comprising:

• first spread code generating means for generating a first spread code;
• second spread code generating means for generating a second spread code;
• transmission timing control means for controlling said first spread code generating means to generate said first spread code for a predetermined period of transmission data fed in for transmission and for controlling said second spread code generating means to generate said second spread code for a predetermined period of said first spread code;
• spreading means for spreading said transmission data by using said first spread code generated at said predetermined period of said transmission data and said second spread code generated at said predetermined period of said first spread code to output a spreading signal;
• and
• transmitting means for performing predetermined processing on said spreading signal to transmit it as a transmitting signal.

In a spread spectrum communication system having a transmitter and a receiver communicating by a spread spectrum communication method, said receiver comprising:

• receiving means for receiving a transmitting signal, in which transmission data is spread by using a first spread code and second spread code, transmitted from said transmitter and producing a receiving signal therefrom;
• first inverse-spread code generating means for generating said first spread code as an inverse-spread code;
• second inverse-spread code generating means for generating said second spread code as an inverse-spread code;
• first correlation detecting means for detecting a correlation between said first spread code and said receiving signal to output a first synchronous timing signal;
• first inverse-spreading means for inverse-spreading said receiving signal by using said first spread code to output a first inverse-spreading signal in accordance with said first synchronous timing signal;
• second correlation detecting means for detecting a correlation between said second spread code and said first signal to output a second synchronous timing signal;
• and
• second inverse-spreading means for inverse-spreading said first inverse-spreading signal by using said second spread code to output a second inverse-spreading signal in accordance with said second synchronous timing signal.

A transmitter in a spread spectrum communication system communicating by a spread spectrum communication method, said transmitter comprising:

• first spread code generating means for generating a first spread code;
• second spread code generating means for generating a second spread code;
• transmission timing control means for controlling said first spread code generating means to generate said first spread code for a predetermined period of transmission data fed in for transmission and for controlling said second spread code generating means to generate said second spread code for a predetermined period of said first spread code;
• spreading means for spreading said transmission data by using said first spread code generated at said predetermined period of said transmission data and said second spread code generated at said predetermined period of said first spread code and for outputting a spreading signal;
• and
• transmitting means for performing a predetermined processing on said spreading signal for transmission as a transmitting signal.

A receiver in a spread spectrum communication system communicating by a spread spectrum communication method, said receiver comprising:

• receiving means for receiving a transmitting signal from a transmission side of said spread spectrum communication system;
• first inverse-spread code generating means for generating a first inverse-spread code of a identical to a first spread code of said transmission side;
• second inverse-spread code generating means for generating a second inverse-spread code for a first specified time of said first inverse-spread code;
• first correlation detecting means for detecting a correlation between said first inverse-spread code and said receiving signal to output a first synchronous timing signal;
• first inverse-spreading means for inverse-spreading said receiving signal by using said first inverse-spread code and for outputting a first inverse-spreading signal in accordance with said first synchronous timing signal;
• second correlation detecting means for detecting a correlation between said second inverse-spread code and said first inverse-spreading signal, to output a second synchronous timing signal;
• and
• second inverse-spreading means for inverse-spreading said first inverse-spreading signal by using said second inverse-spread code and for outputting a second inverse-spreading signal in accordance with said second synchronous timing signal.