Data transmission method using repeated sets of spreading sequences, corresponding transmitter and receiver
View Patent ↗A data transmission process using repetitive sets of spreading sequences, and corresponding transmitter and receiver. Spectrum spreading is performed on symbol packets using sets of pseudo-random sequences used repetitively, thus reducing interference between symbols.
1. A spectrum spreading data transmission process in which:
a step of sending, including building up symbols to be sent from data to be transmitted, and modulating said symbols by spectrum spreading using pseudo-random sequences,
a step of receiving, including correlating a received signal with the pseudo-random sequences used in sending, identifying the sent symbols, and restoring the data,
the process comprising:
a) in said sending step:
v) building up a set of S successive different pseudo-random sequences, in which S is greater than or equal to at least 2,
vi) grouping the symbols to be transmitted into packets each containing S successive symbols,
vii) modulating the S successive symbols by one of the set of S successive different pseudo-random sequences,
viii) repeating said step of modulating for successive packets with a remaining one of the set of S successive different pseudo-random sequences, the pseudo-random sequences in the set thus being used repetitively,
b) in said receiving step:
correlating the received signal with each of the S pseudo-random sequences used in the sending step,
restoring the successive packets of symbols and corresponding data.
2. The process according to claim 1 , in which several packets of S symbols are processed in parallel.
3. A transmitter configured to execute the step of sending recited in claim 1 , comprising a general input ( 10 ), means ( 20 ) for receiving the data to be transmitted and building up symbols, and means ( 60 ) for modulating the symbols by the spectrum spreading using the pseudo-random sequences, said transmitter further comprising:
means ( 50 ) for building up the set of S successive different pseudo-random sequences
means ( 30 , 40 ) for grouping symbols to be transmitted into packets each containing S successive symbols,
the means ( 60 ) for modulating the successive symbols of a packet by S successive pseudo-random sequences of the set of successive different pseudo-random sequences, and for reiterating the modulation for successive packets of symbols, the pseudo-random sequences of the set thus being used repetitively.
4. The transmitter according to claim 3 , in which the means ( 60 ) for modulating are adapted to process several packets of S symbols in parallel.
5. A receiver configured to execute the step of receiving recited in claim 1 , comprising means for correlating the received signal with the pseudo-random sequences and for outputting despread symbols, and means for recovering data from said despread symbols, said receiver further comprising:
means ( 110 1 , . . . 110 M ) for correlating the received signal with S pseudo-random sequences, S being an integer greater than or equal to 2,
means ( 120 1 , . . . 120 M ) ( 130 ) ( 140 1 , . . . , 140 L ) ( 150 1 , . . . , 150 L ) for recovering packets of the S despread symbols,
means ( 170 ) for recovering the transmitted data from said packets of the S despread symbols.
6. The receiver according to claim 5 , in which the means ( 120 1 , . . . , 120 M ) ( 130 ) ( 140 1 , . . . , 140 L ) ( 150 1 , . . . , 150 L ) for recovering are adapted to process several packets of successive symbols in parallel.