US 5,325,394 A · Method and apparatus for canceling spread-spectrum noise

Abstract

A spread-spectrum noise canceller (182) is provided. A received phase and a received amplitude for a first (216) and a second (236) component of a received spread-spectrum signal (200) is determined. The second component (236) is structurally similar to [a replica of] the first component (216), but differs by being received at a different time, being transmitted along a different path, or having a different phase [which was received at a different time]. In addition, the spread-spectrum signal (200) includes a first and a second known signal. A portion of a spread-spectrum noise signal in the received signal (200) is canceled by generating an estimated signal (270) by spreading (260) the second known signal at the second component received phase (204) with the first known signal at the first component received phase (224) and adjusting a gain (268) of an integrated form of the spread second known signal as a function of the received amplitudes of the first (216) and the second (236) components. Subsequently, the second known signal is processed out of the received spread-spectrum signal (200) by subtracting (166) the estimated signal (270) from a demodulated form (216, 236) of the received spread-spectrum signal (200).

Claims20

Dependent claims

An apparatus comprising a spread-spectrum noise canceller, the spread-spectrum noise canceller comprising:

(a) determining means for determining a received phase and a received amplitude for a first and a second component of a received spread-spectrum signal, the first component being different from the second component, the spread-spectrum signal including a first and a second known signal;
and
(b) noise cancelling means, operatively coupled to the determining means, for cancelling a portion of a spread-spectrum noise signal in the received spread-spectrum signal by:
(i) generating an estimated signal by spreading the second known signal at the second component received phase with the first known signal at the first component received phase and adjusting a gain of an integrated form of the spread second known signal as a function of the received amplitudes of the first and the second components;
and
(ii) processing the second known signal out of the received spread-spectrum signal by subtracting the estimated signal from a demodulated form of the received spread-spectrum signal.

3 more elements

An apparatus comprising a spread-spectrum noise canceller, the spread-spectrum noise canceller comprising:

(a) receiving means for receiving a spread-spectrum signal having a first and a second component from over a communication channel, the first component being different from the second component, the spread-spectrum signal including a first and a second known signal;
(b) determining means, operatively coupled to the receiving means, for determining a received phase and a received amplitude for the first and the second components of a received spread-spectrum signal;
(c) demodulating means, operatively coupled to the receiving means, for demodulating the received spread-spectrum signal;
and
(d) noise cancelling means, operatively coupled to the determining means and the demodulating means, for cancelling a portion of a spread-spectrum noise signal in the received spread-spectrum signal by:
(i) generating an estimated signal by spreading the second known signal at the second component received phase with the first known signal at the first component received phase, integrating the spread second known signal over a predetermined time, and adjusting a gain of the integrated spread second known signal as a function of the received amplitudes of the first and the second components;
and
(ii) processing the second known signal out of the received spread-spectrum signal by subtracting the estimated signal from the demodulated received spread-spectrum signal.

5 more elements

A spread-spectrum signal processing method, comprising:

(a) determining a received phase and a received amplitude for a first and a second component of a received spread-spectrum signal, the first component being different from the second component, the spread-spectrum signal including a first and a second known signal;
and
(b) canceling a portion of a spread-spectrum noise signal in the received spread-spectrum signal by:
(i) generating an estimated signal by spreading the second known signal at the second component received phase with the first known signal at the first component received phase and adjusting a gain of an integrated form of the spread second known signal as a function of the received amplitudes of the first and the second components;
and
(ii) processing the second known signal out of the received spread-spectrum signal by subtracting the estimated signal from a demodulated form of the received spread-spectrum signal.