Variable chip rate code-division multiple access

Details Variable chip rate code-division multiple access Variable chip rate code-division multiple access

1999-03-10

2000-07-11

Felber, Joseph L.

Multiplex communications

Communication over free space

Combining or distributing information via code word channels...

370441, 375146, H04B 7216

Patent

active

060883472

ABSTRACT:
A method of communicating multiple signals over a common communications link by modulating first input signals with respective first codes of low cross-correlation to obtain a first set of modulated signals at a first chip rate. The input signals can be, for example, digitized audio or video signals, or data signals. The second input signals are of a data rate higher than the first input signals, and the second codes are of a dimension greater than the first codes. The second input signal or signals are modulated with respective second codes of low cross correlation relative to each other and relative to the first codes, resulting in a second set of modulated signals at a second chip rate such that there is spectral overlap between the first and second sets of modulated signals. The first and second sets of modulated signals are preferably modulated with different noise signals to spread the spectrum of each. In a preferred embodiment, the first and second codes are Walsh codes of different dimensions.

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