Spread spectrum communication

Claim 3

The method of claim 1 , wherein: the seed set contains binary sequences.

Claim 4

The method of claim 2 , wherein: the binary sequence is cyclically distinct, quasi-balanced and satisfies the optimal periodic autocorrelation condition.

Claim 5

The method of claim 1 , wherein: the seed set contains complex sequences.

Claim 6

The method of claim 1 , wherein: the seed set is orthogonal.

Claim 7

The method of claim 1 , wherein: the subset of sequences is constructed by concatenating the sequences of a coset using an addition table.

Claim 8

The method of claim 6 , wherein: the addition table is constructed using powers of a primitive root of the seed set of sequences, the primitive root being determined in accordance with the size of the seed set.

Claim 9

The method of claim 6 , wherein: the addition table is constructed using powers of a primitive element of the seed set of sequences, the primitive element being determined in accordance with the size of the seed set.

Claim 10

The method of claim 1 , wherein: the seed set is formed from a plurality of rotated sequences.

Claim 13

The method of claim 10 , wherein: the seed set contains binary sequences.

Claim 14

The method of claim 11 , wherein: the binary sequence is cyclically distinct, quasi-balanced and satisfies the optimal periodic autocorrelation condition.

Claim 15

The method of claim 11 , wherein: the seed set contains complex sequences.

Claim 16

The method of claim 10 , wherein: the seed set is orthogonal.

Claim 17

The method of claim 10 , wherein: the subset of sequences is constructed by concatenating the sequences of a coset using an addition table.

Claim 18

The method of claim 15 , wherein: the addition table is constructed using powers of a primitive root of the seed set of sequences, the primitive root being determined in accordance with the size of the seed set.

Claim 19

The method of claim 15 , wherein: the addition table is constructed using powers of a primitive element of the seed set of sequences, the primitive element being determined in accordance with the size of the seed set.

Claim 20

The method of claim 10 , wherein: the seed set is formed from a plurality of rotated sequences.

Claim 23

The apparatus of claim 19 , wherein: the seed set generating means comprises a plurality of shift registers, each shift register having an input, a system clock input, logic gates, a plurality of register cells/stages and an output to form a sequence of the seed set.

Claim 24

The apparatus of claim 19 , wherein: the seed set generating means includes a number of linear feedback shift registers.

Claim 25

The apparatus of claim 19 , wherein the expansion means comprises: a plurality of inputs, each input corresponding to a sequence from a coset; a plurality of multiplexers having associated counters and logic gates; a system clock input; and a plurality of outputs to form a subset of sequences.

Claim 26

An apparatus in accordance with claim 19 for decoding signature sequences in a spread spectrum communications system, comprising: means for receiving coded signals; means for generating sequence functions; means for combining received coded signals with sequence functions to produce despread signal outputs; means for combining the despread signal outputs to generate a data stream; and logic circuitry for analysing the data stream.

Claim 27

A data transmission system, comprising: a transmitter and a receiver, the transmitter incorporating means for transmitting data using a signature sequence and the receiver formed for receiving and decoding data transmitted using a signature sequence, the signature sequence being generated by performing the steps of: selecting a seed set of sequences of a given size; generating a plurality of cosets from the seed set of sequences; constructing a subset of sequences by concatenating the sequences of a coset; and constructing a full set of sequences by concatenating subsets of sequences.

Claim 28

A data transmission system, comprising: a transmitter and a receiver, the transmitter incorporating means for transmitting data using a signature sequence and the receiver formed for receiving and decoding data transmitted using a signature sequence, the signature sequence being generated by performing the steps of: selecting a seed set of sequences of a given size; generating a plurality of cosets from the seed set of sequences; constructing a subset of sequences by concatenating the sequences of a coset; and constructing a full set of sequences by concatenating subsets of sequences.

Claim 29

An electromagnetic radiation or sonic communications system for a communications network comprising a plurality of remote communication terminals, each terminal including a transmitter circuit having means for generating and encoding signature sequences for spread spectrum communication techniques by performing the steps of: selecting a seed set of sequences of a given size having a plurality of inner sequences, generating a plurality of cosets from the seed set of sequences by multiplying in turn each inner sequence by an element of an associated sequence, constructing a subset of sequences by concatenating the sequences of a coset and constructing a full set of sequences by concatenating subsets of sequences, the transmitter circuit also having, a means for transmitting coded signals and a receiver circuit for receiving coded signals the receiver circuit having means for decoding signature sequences in a spread spectrum communication system.

Claim 30

An electromagnetic radiation or sonic communications system for a communications network comprising a plurality of remote communication terminals, each terminal including a transmitter circuit having means for generating and encoding signature sequences for spread spectrum communication techniques by performing the steps of: selecting a seed set of sequences of a given size having a plurality of inner sequences, generating a plurality of cosets from the seed set of sequences by multiplying in turn each inner sequence by an element of an associated sequence, constructing a subset of sequences by concatenating the sequences of a coset and constructing a full set of sequences by concatenating subsets of sequences, the transmitter circuit also having, a means for transmitting coded signals and a receiver circuit for receiving coded signals the receiver circuit having means for decoding signature sequences in a spread spectrum communication system.

Claim 31

The system of claim 25 , wherein: the communications network uses a radio frequency carrier.

Claim 32

The system of claim 25 , wherein: the communications network uses an ultrasound carrier.

Claim 33

The system of claim 25 , wherein: the communications network uses a seismic carrier.

Claim 34

The system of claim 25 , wherein: the communications network uses a lightwave carrier.

Claim 35

The system of claim 29 , wherein: the communications network uses an infrared carrier.

Claim 36

The system of claim 29 , wherein: the receiver circuit incorporates a photodetector, the photodetector having an associated coupling means communicating with a receiver preamplifier.

Claim 37

The system of claim 31 , wherein: the coupling means is formed for differential signal recognition.

Claim 38

The system of claim 25 , wherein: the seed set is a balanced seed set.

Claim 39

The system of claim 25 , wherein: the encoding signature sequences incorporates orthogonal structured codes.