Spread spectrum receiver having phase shifter for effecting phase synchronization of two convolvers
First Claim
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1. A spread-spectrum receiver, comprising:
- a correlator which includes first and second convolvers each having first and second inputs, said first inputs each being supplied with a common spread-spectrum received signal;
first multiplier means for applying a first reference signal produced by multiplication of a first CW signal and a first PN code to said second input of said first convolver;
signal distributing means supplied with said first CW signal for distributing said first CW signal into first and second signals which are different in phase by 90 degrees;
function signal generating means responsive to a predetermined digital signal for generating a sine function signal and a cosine function signal;
weighting means for weighting said first and second signals by said sine function signal and said cosine function signal, respectively;
adder means for adding said weighted first and second signals from said weighting means to generate a second CW signal which has the same frequency as and a predetermined phase difference from said first CW signal;
second multiplier means for applying a second reference signal produced by multiplication of said second CW signal and a second PN code to said second input of said second convolver; and
demodulating means for demodulating data by multiplying outputs of both of said convolvers.
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Abstract
A phase shifter is disclosed which performs a desired phase shift by distributing an input signal to two signals whose phases are different by 90° from each other which signals are added to each other after having been weighted with a sine and a cosine function signal, the sine and the cosine function signal being able to be set in a digital manner.
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4 Claims
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1. A spread-spectrum receiver, comprising:
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a correlator which includes first and second convolvers each having first and second inputs, said first inputs each being supplied with a common spread-spectrum received signal; first multiplier means for applying a first reference signal produced by multiplication of a first CW signal and a first PN code to said second input of said first convolver; signal distributing means supplied with said first CW signal for distributing said first CW signal into first and second signals which are different in phase by 90 degrees; function signal generating means responsive to a predetermined digital signal for generating a sine function signal and a cosine function signal; weighting means for weighting said first and second signals by said sine function signal and said cosine function signal, respectively; adder means for adding said weighted first and second signals from said weighting means to generate a second CW signal which has the same frequency as and a predetermined phase difference from said first CW signal; second multiplier means for applying a second reference signal produced by multiplication of said second CW signal and a second PN code to said second input of said second convolver; and demodulating means for demodulating data by multiplying outputs of both of said convolvers. - View Dependent Claims (2, 3, 4)
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Specification