Sequence constructions for delay-and-correlate transmitted reference signaling

Claim 2

In a direct conversion delay-and-correlate transmitted reference spread spectrum signaling system, a transmitter comprising: a sequence generator for generating a sequence signal characterized as x(1),x(2),x(3), . . . ,x(N), where x(j) are elements of the sequence, said sequence generator being adapted to modify the sequence signal to generate an enhanced sequence signal having improved autocorrelation properties; a first multiplier for generating a first product signal by multiplying the sequence signal from the sequence generator and input data to be transmitted; a first delay device for delaying the product signal from said multiplier by a delay d, where twice the delay, 2d, is an odd number of chip intervals; a summer for generating a summed signal for summing the delayed product signal with the sequence signal from said sequence generator; and first radio frequency means, including a mixer, for converting said summed signal to a signal for transmission.

Claim 3

The apparatus of claim 1 wherein said sequence generator is adapted to alter the sequence signal by replacing the term at 2d+j with x(j), j odd, over the length of the sequence, starting at 2d+1 to produce the sequence x(1),x(2),x(3), . . . x(2d),x(1), x(2d+2) ,x(3),x(2d+4),x(5), . . . that will provide a desirable autocorrelation peak at 2d.

Claim 4

The apparatus of claim 1 further comprising: a receiver including second radio frequency means, including a mixer, for converting a received signal to a baseband signal; a second delay device coupled to the output of the second radio frequency means for delaying said baseband signal by a delay d; a second multiplier for generating a second product signal by multiplying the baseband signal by the baseband signal delayed by delay d; and a data detector responsive to said second product signal for detecting transmitted data.

Claim 5

The apparatus of claim 3 wherein the multiplication performed by said second multiplier is p(t)+m(t-d)p(t-d)!x p(t-d)+m(t-2d)p(t-2d)!=p(t)p(t-d)+p(t)p(t-2d)m(t-2d)+m(t-d)p(t-d)p(t-d)+m(t-d)p(t-d)p(t-2d)m(t-2d), where p(t) is a reference signal and m(t) is a message signal, and wherein the delay is such that the second term is small relative to a symbol interval producing a strong autocorrelation of p(t) at delay 2d.

Claim 6

A direct conversion delay-and-correlate transmitted reference spread spectrum signaling system comprising: a transmitter including a sequence generator for generating a sequence signal characterized as x(1),x(2),x(3), . . . ,x(N), where x(j) are elements of the sequence, said sequence generator being adapted to modify the sequence signal to generate an enhanced sequence signal having improved autocorrelation properties; first multiplier for generating a first product signal by multiplying the sequence signal from the sequence generator and input data to be transmitted; a first delay device for delaying the product signal from said multiplier by a delay d, where twice the delay, 2d, is an odd number of chip intervals; a summer for generating a summed signal for summing the delayed product signal with the sequence signal from said sequence generator; and first radio frequency means, including a mixer, for converting said summed signal to a signal for transmission; said sequence generator being adapted to alter the sequence signal by replacing the term at 2d+j with x(j), j odd, over the length of the sequence, starting at 2d+1 to produce the sequence x(1),x(2),x(3), . . . x(2d),x(1), x(2d+2) ,(3),x(2d+4),x(5), . . . that will provide a desirable autocorrelation peak at 2d; and a receiver including second radio frequency means, including a mixer, for converting a received signal to a baseband signal; a second delay device coupled to the output of the second radio frequency means for delaying said baseband signal by a delay d; a second multiplier for generating a second product signal by multiplying the baseband signal by the baseband signal delayed by delay d, wherein the multiplication performed by said second multiplier is p(t)+m(t-d)p(t-d)!x p(t-d)+m(t-2d)p(t-2d)!=p(t)p(t-d)+p(t)p(t-2d)m(t-2d)+m(t-d)p(t-d)p(t-d)+m(t-d)p(t-d)p(t-2d)m(t-2d), where p(t) is a reference signal and m(t) is a message signal, and wherein the delay is such that the second term is small relative to a symbol interval producing a strong autocorrelation of p(t) at delay 2d; and a data detector responsive to said second product signal for detecting transmitted data.

Claim 7

A direct conversion delay-and-correlate transmitted reference spread spectrum signaling system comprising: a transmitter including a sequence generator for generating a sequence signal characterized as x(1),x(2),x(3), . . . ,x(N), where x(j) are elements of the sequence, said sequence generator being adapted to modify the sequence signal to generate an enhanced sequence signal having improved autocorrelation properties; first multiplier for generating a first product signal by multiplying the sequence signal from the sequence generator and input data to be transmitted; a first delay device for delaying the product signal from said multiplier by a delay d, where twice the delay, 2d, is an odd number of chip intervals; a summer for generating a summed signal for summing the delayed product signal with the sequence signal from said sequence generator; and first radio frequency means, including a mixer, for converting said summed signal to a signal for transmission; said sequence generator being adapted to alter the sequence signal by replacing the term at 2d+j with x(j), j odd, over the length of the sequence, starting at 2d+1 to produce the sequence x(1),x(2),x(3), . . . x(2d),x(1), x(2d+2) ,(3),x(2d+4),x(5), . . . that will provide a desirable autocorrelation peak at 2d; and a receiver including second radio frequency means, including a mixer, for converting a received signal to a baseband signal; a second delay device coupled to the output of the second radio frequency means for delaying said baseband signal by a delay d; a second multiplier for generating a second product signal by multiplying the baseband signal by the baseband signal delayed by delay d, wherein the multiplication performed by said second multiplier is p(t)+m(t-d)p(t-d)!x p(t-d)+m(t-2d)p(t-2d)!=p(t)p(t-d)+p(t)p(t-2d)m(t-2d)+m(t-d)p(t-d)p(t-d)+m(t-d)p(t-d)p(t-2d)m(t-2d), where p(t) is a reference signal and m(t) is a message signal, and wherein the delay is such that the second term is small relative to a symbol interval producing a strong autocorrelation of p(t) at delay 2d; and a data detector responsive to said second product signal for detecting transmitted data.