Method and apparatus for transmission of variable rate digital data

A method for transmitting a variable rate data packet of data symbols, said method comprising the steps of:

• receiving said packet;
• when the number of said data symbols in said packet is less than a first value generating duplicates of said data symbols and combining said data symbols and said duplicates of said data symbols in said packet;
• when the number of data symbols in said packet equals said first value, transmitting said packet at a first energy level;
• when the number of data symbols in said packet is less than said first value and greater than a second value, transmitting said packet at a second energy level which is less than said first energy level;
• and
• when the number of data symbols in said packet is less than said second value gating ones of said data symbols and said duplicates of said data symbols and transmitting said packet at a third energy level.

A system for transmitting a variable rate data packet of data symbols, said system comprising:

• a repetition generator having an input and having an output;
• a transmitter having an input coupled to said repetition generator output and having an output;
• a spread spectrum modulator interposed between said repetition generator and said transmitter having an input coupled to said repetition generator output and having an output coupled to said transmitter input, said spread spectrum modulator comprising:
• a first PN generator having an output;
• and
• a first mixer having a first input coupled to said repetition generator output and having a second input coupled to said first PN generator output and having an output.