RF broadcasting employing sinusoidal-cosine wave generation with plural look-up tables

• US 20060253511A1
• Filed: 05/06/2005
• Published: 11/09/2006
• Est. Priority Date: 05/06/2005
• Status: Abandoned Application

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Abascal, Carlos Garcia, Mattsson, Anders S.
• Application Number:
  US11/123,990
• Publication Number:
  US 20060253511A1
• Time in Patent Office: Days
• US Class Current: 708/270
• CPC Class Codes: G06F 1/0356 by using two or more smaller tables, e.g. addressed by parts of the argument
• CPC Class Codes: H04B 1/00 Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission

Abstract

An RF broadcasting system is presented that employs sinusoidal wave generation with look-up tables. The system includes a base band signal generator that converts a received N bit digital base band signal into an N bit digital address based on the base band signal. A signal processor is included having a plurality of addressable look-up tables that provide sinusoidal wave generating data, each of the tables receiving the address and providing therefrom multi-bit wave generating data. The processor also includes multipliers and summer means all configured and arranged to perform the algorithm:
Cos [a+b]=Cos [a]·Cos [b]−Sin [a]·Sin [b]or the algorithm:
Sin [a+b]=Cos [b]·Sin [a]+Cos [a]·Sin [b]for use in the generation.

Claims

1. An RF broadcasting system employing sinusoidal wave generation with look-up tables and comprising:

a base band signal generator that converts a received N bit digital base band signal into an N bit digital address based on said base band signal;

a signal processor including a plurality of addressable look-up tables that provide sinusoidal wave generating data, each of said tables receiving said address and providing therefrom multi-bit wave generating data, said processor also including multipliers and summer means all configured and arranged to perform the algorithm;

Cos [a+b]=Cos [a]·

Cos [b]−

Sin [a]·

Sin [b]

or the algorithm;

Sin [a+b]=Cos [b]·

Sin [a]+Cos [a]·

Sin [b]

for use in said generation.

2. A system as set forth in claim 1 wherein N is at least 16.

3. A system as set forth in claim 1 wherein said plurality of look-up tables includes four look-up tables each storing a plurality of wave generating sample data.

4. A system as set forth in claim 3 including two said multipliers.

5. A system as set forth in claim 4 wherein said summing means includes a summer-adder.

6. A system as set forth in claim 3 wherein N is equal to at least 16.

7. A system as set forth in claim 6 wherein each said look-up table stores 256 wave generating sample data.