Low cost DSSS communication system

Details Low cost DSSS communication system Low cost DSSS communication system

2001-12-21

2003-05-13

Ghayour, Mohammad H. (Department: 2634)

Pulse or digital communications

Spread spectrum

Direct sequence

C375S145000, C375S147000, C375S149000

Reexamination Certificate

active

06563857

ABSTRACT:

TECHNICAL FIELD
This invention relates to techniques and apparatus for wireless communication using Direct Sequence Spread Spectrum (DSSS) techniques.
BACKGROUND OF THE INVENTION
In the transmitter of a direct-sequence spread spectrum communication systems, a carrier waveform is modulated by a data sequence x(n) and by a spreading sequence or code sequence C(n). The code sequence may be a pseudo-noise (PN) sequence, such as a maximum length sequence (m-sequence). The PN sequence is used to reduce the sensitivity of the communication channel to noise, reduce the power spectral density of the signal and to allow multiple communication channels to operate simultaneously. In the latter case, each channel is assigned its own PN code sequence, so the technique is called code-division multiple access (CDMA).
In the receiver the data signal is recovered by removing the carrier wave and then correlating the received signal with the PN code sequence used for transmission. Decorrelation requires a large amount of computation to align the received signal with the PN code sequence, and so adds to the cost of the receiver.
In view of the preceding remarks, it is clear that there is an unmet need in the art for a receiver that avoids the high cost of performing a correlation between the received signal and a PN code sequence.


REFERENCES:
patent: 5222075 (1993-06-01), Richley
patent: 5412620 (1995-05-01), Cafarella et al.
patent: 5559828 (1996-09-01), Armstrong et al.
patent: 5610940 (1997-03-01), Durrant et al.
patent: 6111911 (2000-08-01), Sanderford, Jr. et al.

Affiliated with

Also associated with

Rating

Low cost DSSS communication system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Low cost DSSS communication system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low cost DSSS communication system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3057829