Spread spectrum receiver

• US 5,132,985 A
• Filed: 07/03/1991
• Issued: 07/21/1992
• Est. Priority Date: 07/04/1990
• Status: Expired due to Fees

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Clarion Co., Ltd. (Faurecia SA)
• Inventors: Hashimoto, Takeshi, Uchida, Yoshitaka
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US07/725,530
• Time in Patent Office: 384 Days
• Field of Search: 375/80, 375/82, 375/94, 375/96
• US Class Current: 375/151
• CPC Class Codes: H04B 1/70712 with demodulation by means of convolvers, e.g. of the SAW type SAW convolvers in general G06G7/195
• CPC Class Codes: H04B 1/709 Correlator structure

Abstract

A spread spectrum receiver has first and second correlators which each compare a received signal with a respective reference signal. The output of each correlator is routed through a respective band pass filter and a respective AGC amplifier to a respective detector circuit which converts the output of the amplifier into a respective base band signal. The ouput of each detector circuit is supplied to a respective peak value detecting and holding section, which detects and holds for a predetermined time period peak values from the associated detector circuit. Each peak value detecting and holding circuit supplies the peak value currently held therein through a respective low pass filter which serves as an integrator to a data comparing section and to an adding section. The adding section adds the two peak values, and supplies the sum to control inputs of each of the AGC amplifiers for purposes of gain control. The data comparing circuit compares the peak values and produces an output which is demodulated data from the received signal.

Claims

1. A spread spectrum receiver comprising:

first reference signal generating means for generating a first reference signal;

second reference signal generating means for generating a second reference signal;

a first correlator for making correlation between a received signal and said first reference signal and for producing a correlation spike when the correlation has been made;

a second correlator for making correlation between said received signal and said second reference signal and for producing a correlation spike when the correlation has been made;

first and second converting means for respectively converting outputs of said first and said second correlators into respective first and second base band signals;

first and second peak value holding means for holding for a predetermined period of time peak values of outputs respectively from said first and said second converting means, said first peak value holding means supplying to an output thereof the peak value held therein, and said second peak value holding means supplying to an output thereof the peak value held therein; and

a data comparing section for comparing said output of said first peak value holding means with said output of said second peak value holding means to reproduce data.

2. A spread spectrum receiver according to claim 1, further comprising first and second integrating means for respectively integrating outputs of said first and said second peak value holding means, said first integrating means being disposed between said first peak value holding means and said data comparing section, and said second integrating means being disposed between said second peak value holding means and said data comparing section.

3. A spread spectrum receiver according to claim 2, wherein:

each of said first and said second converting means includes a detector; and

each of said first and said second integrating means includes a low pass filter.

4. A spread spectrum receiver according to claim 1, further comprising:

first and second AGC amplifiers, said first AGC amplifier being disposed between said first correlator and said first peak value holding means, and said second AGC amplifier being disposed between said second correlator and said second peak value holding means; and

adding means for combining outputs of said first and said second peak value holding means.