Preamble code structure and detection method and apparatus

A method of communicating among a plurality of stations comprising the steps of:

• selecting a first subcode and a second subcode having low cross-correlation properties;
• generating a first repeated codeword preamble code from a repeated series of said first subcode, said first repeated codeword preamble code comprising a first single continuous code;
• generating a second repeated codeword preamble code from a repeated series of said second subcode said second repeated codeword preamble code comprising a second single continuous code;
• and
• communicating among the plurality of stations using said first repeated codeword preamble code and said second repeated codeword preamble code as preambles preceding data messages;
• generating a first odd-length code;
• modifying a length of said first odd-length code by one chip to form said first subcode,
• generating a second odd-length code;
• and
• modifying a length of said second odd-length code by one chip to form said second subcode.

A communication system, comprising:

• a first station, said first station comprising a transmitter for transmitting a preamble code and a data message, said preamble code comprising a kronecker product of a first subcode and a second subcode;
• and
• a second station, said second station comprising a receiver for receiving said preamble code, synchronizing in response to said preamble code, and receiving said data message;
• wherein said receiver of said second station comprises
• a first correlator for correlating said preamble signal against said first subcode and generating a first correlation output signal in response thereto, said first correlation output signal comprising a first correlator correlation pulse corresponding to each occurrence of said first subcode or its inverse in said preamble code;
• and
• a second correlator for correlating said first correlation output signal against said second subcode and generating a second correlation output signal in response thereto, said second correlation output signal comprising a second correlator correlation pulse when said preamble code is fully received.

A station for communication, comprising:

• a receiver for receiving a repeated codeword preamble code and a data message, said repeated codeword preamble code comprising a repeated series of the same subcode;
• a correlator for generating a plurality of correlation spikes in response to receiving said repeated codeword preamble code, each of said correlation spikes corresponding to a separate appearance of said subcode;
• means for detecting receipt of said repeated codeword preamble code upon simultaneous detection of more than one of said correlation spikes;
• and
• means for synchronizing the receiver in response to said repeated codeword preamble code.

A communication system, comprising:

• first station, said first station comprising a first transmitter for transmitting a first concatenated code generated from a kronecker product of a first subcode and a second subcode;
• a second station, said second station comprising a second transmitter for transmitting a second concatenated code generated from a kronecker product of a third subcode and a fourth subcode, said second concatenated code having the same length as said first concatenated code;
• a first receiver, said first receiver configured to receive said first concatenated code;
• and
• a second receiver, said second receiver configured to receive said second concatenated code.

A communication system, comprising:

• a first station, said first station comprising a first transmitter for transmitting a first concatenated code generated from a kronecker product of a first subcode and a second subcode, said first subcode being an inner code in said kronecker product and said second subcode being an outer code in said kronecker product;
• a second station, said second station comprising a second transmitter for transmitting a second concatenated code generated from a kronecker product of said first subcode and said second subcode, said first subcode being the outer code in said second kronecker product and said second subcode being the inner code in said second kronecker product, said second concatenated code having the same length as the first concatenated code;
• a first receiver, said first receiver configured to detect said first concatenated code;
• and
• a second receiver, said second receiver configured to detect said second concatenated code.

A communication system, comprising:

• a first station, said first station comprising a first transmitter for transmitting a first concatenated code generated from a product of a first subcode and a first Barker code;
• a second station, said second station comprising a second transmitter for transmitting a second concatenated code having the same length as said first concatenated code, said second concatenated code generated from a product of a second subcode and a second Barker code;
• a first receiver, said first receiver configured to detect said first concatenated code;
• and
• a second receiver, said second receiver configured to detect said second concatenated code.

A communication system, comprising:

• first station, said first station comprising a first transmitter for transmitting a first repeated codeword preamble code generated from a repeated series of a first subcode;
• a second station, said second station comprising a second transmitter for transmitting a second repeated codeword preamble code generated from a repeated series of a second subcode, said second subcode having relatively low cross-correlation properties with respect to said first subcode;
• a first receiver, said first receiver configured to detect said first repeated codeword preamble code;
• and
• a second receiver, said second receiver configured to detect said second repeated codeword preamble code.

A communication system, comprising:

• first station, said first station comprising a first transmitter for transmitting a first preamble code and a first data message, said first preamble code generated from a series of a first subcode;
• a second station, said second station comprising a second transmitter for transmitting a second preamble code and a second data message, said second preamble code generated from a series of a second subcode, wherein said second subcode has the same length as said first subcode and a low cross-correlation level with respect said first subcode, and wherein said first preamble code and said second preamble code have the same length;
• a first receiver for receiving said first preamble code and said first data message, and for synchronizing to said first preamble code;
• and
• a second receiver for receiving said second preamble code and said second data message, and for synchronizing to said second preamble.