Bipolar waveform modulation for ultra wideband (UWB) communication networks

• US 20050058210A1
• Filed: 09/16/2003
• Published: 03/17/2005
• Est. Priority Date: 09/16/2003
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Fischer, Gerald R., Berger, Harvey L.
• Granted Patent: US 7,342,971 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/7176 Data mapping, e.g. modulation

Abstract

A method for ultra wideband (UWB) communication in which UWB pulses encode binary data as either normal or inverted (anti-podal) pulses. In the case of pulses of a carrier signal, each pulse has the carrier signal either inverted or in phase, that is, shifted by 180°, or not. For example, a binary “1” may be encoded as a normal or non-inverted pulse and a binary “0” as an inverted pulse. After each carrier pulse is rectified and filtered, detection is effected using a threshold value of zero, resulting in increased immunity to noise, compared with detection of unidirectional pulses. In one aspect of the invention, data pertaining to multiple communication channels are encoded in time-divided portions of each UWB pulse.

Claims

1. For use in an ultra wideband (UWB) communication system, a method for communicating binary data, having logical “

0” and

“

1”

value types, as a sequence of UWB pulses, the method comprising;

encoding binary data of one value type as positive UWB pulses and binary of the other value type as negative UWB pulses; and

detecting the presence of positive and negative UWB pulses using a zero-level sensing threshold, thereby increasing immunity to noise.

2. A method as defined in claim 1, wherein:

each UWB pulse includes a carrier signal; and

each negative UWB pulse has its carrier phase inverted.

3. A method as defined in claim 2, wherein the detecting step comprises:

sensing whether the carrier phase is inverted or not;

rectifying and filtering the UWB carrier signal pulse to provide a unidirectional signal; and

adjusting the polarity of the unidirectional signal based on whether the sensed carrier phase is inverted or not.

4. A method as defined in claim 3, wherein:

the UWB pulses are generated in predetermined time slots; and

the method further comprises assigning portions of each time slot to respective communication channels, whereby data signals pertaining to multiple communication channels are transmitted in a single time slot.

5. A method as defined in claim 4, wherein:

each UWB pulse time slot has two half time slots;

data signals pertaining to first and second communication channels are encoded in the first and second halves, respectively, of each UWB pulse time slot.