US 5,499,265 A · Spread spectrum correlator

Abstract

An apparatus for decoding a received spread spectrum signal having a data signal modulated with a pseudo-noise code and transmitted as an RF spread spectrum signal. A first reference register holds a first pseudo-noise signal, a second reference register holds a second pseudo-noise signal, and a receive-register holds a received spread spectrum signal. A first modulo adder adds each chip of the received spread spectrum signal with each respective chip of the first pseudo-noise signal, thereby generating a first plurality of chip-comparison signals. A first summer adds the first plurality of chip-comparison signals, generating a first correlation signal. The comparator compares the correlation signal to an upper-threshold level and a lower-threshold level, and respectively generates a first data-symbol signal or a second data-symbol signal.

Claims20

Dependent claims

Apparatus for decoding a spread spectrum signal, said spread spectrum signal having a data signal modulated with the entirety of a pseudo-noise code, said apparatus comprising

a plurality of receiving registers capable of storing a received spread spectrum signal comprising a first plurality of chips,
a plurality of reference registers capable of storing an entire pseudo-noise code comprising a second plurality of chips,
a plurality of adders, each of said adders connected to one of said plurality of receiving registers and one of said plurality of reference registers, each of said adders having an output connected to a summer, said summer outputting a correlation signal, and
a data generator responsive to said correlation signal, generating, at selected clock times, a first data symbol in response to a comparison of said correlation signal and a first predetermined threshold level, and a second data symbol at said clock times in response to a comparison of said correlation signal and a second predetermined threshold level.

1 more element

Dependencies are inferred from the claim text.

Spread spectrum correlator

Life of this patent

Spread spectrum correlator

Life of this patent

Abstract

Claims20