US2004190645A1

2G

Title

System for processing digitized communication signals provided over plural RF channels

Application Number:

US20040818239

Publication Date:

30-09-2004

Current Assignee:

INTERDIGITAL INC

Family ID:

27014763

Application Date:

05-04-2004

Publication Country:

US

View on Espacenet

Priority Date:

14-08-1989

Declaring Company:

INTERDIGITAL INC

Abstract  Abstract

A wireless digital subscriber communications system includes a base station and a subscriber unit and uses communications signals provided over a plurality of radio frequency channels. A processor provides an output phase signal corresponding to a selected output digital frequency, and a lookup table is used having two sets of predefined stored values pertaining to the amplitude of a signal for a single quadrant. In particular embodiments, predefined stored values include coarse angle approximations and fine angle approximations and a sine and cosine generator receives the phase signal and generates sine and cosine waveforms utilizing amplitude values obtained from the lookup table. In a further embodiment, the phase signal includes phase data and specifies the quadrant and the algebraic sign of the phase data, with the sine and cosine generator accessing the lookup table differently depending upon the quadrant and sine of the phase data, such that the lookup table provides an amplitude value from the sets of predefined stored values based on the phase data. A modulator combines the sine and cosine waveforms to produce the selected output digital frequency and modulates digital frequency.

Note:

The information in blue was extracted from the third parties (Standard Setting Organisation, Espacenet)

The information in grey was provided by the patent holder

The information in purple was extracted from the FrandAvenue

Explicitly disclosed patent

Implicitly disclosed patent

Basis patent

Family member

© 2021 All Rights Reserved FrandAvenue