Ultra wide bandwidth communications method and system

• US 7,280,607 B2
• Filed: 11/27/2002
• Issued: 10/09/2007
• Est. Priority Date: 12/12/1997
• Status: Expired due to Fees

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: McCorkle, John W., Rofheart, Martin
• Primary Examiner(s): Fan, Chieh M.
• Assistant Examiner(s): PUENTE, EVA YI ZHENG
• Application Number:
  US10/305,109
• Publication Number:
  US 20030161411A1
• Time in Patent Office: 1,777 Days
• Field of Search: 375/295, 375/130, 375/131, 375/140, 375/146, 375/147, 375/149, 375/200, 375/210, 375/354, 370/207, 370/324, 342/28, 382/340, 714/776
• US Class Current: 375/295
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/7174 Pulse generation in general H04L25/03834
• CPC Class Codes: H04B 1/7183 Synchronisation
• CPC Class Codes: H04B 1/74 for increasing reliability, e.g. using redundant or spare channels or apparatus replacing by standby devices for amplifiers H03F1/52, H03F1/542
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 27/0004 using wavelets

Abstract

An ultra wide bandwidth, high speed, spread spectrum communications system uses short wavelets of electromagnetic energy to transmit information through objects such as walls or earth. The communication system uses baseband codes formed from time shifted and inverted wavelets to encode data on a RF signal. Typical wavelet pulse durations are on the order of 100 to 1000 picoseconds with a bandwidth of approximately 8 GHz to 1 GHz, respectively. The combination of short duration wavelets and encoding techniques are used to spread the signal energy over a an ultra wide frequency band such that the energy is not concentrated in any particular narrow band (e.g. VHF: 30-300 MHz or UHF: 300-1000 MHz) and is not detected by conventional narrow band receivers so it does not interfere with those communication systems. The use of pulse codes composed of time shifted and inverted wavelets gives the system according to the present invention has a spatial resolution on the order of 1 foot which is sufficient to minimize the negative effects of multipath interference and permit time domain rake processing.

Claims

1. An apparatus for transmitting data comprising:

wavelet generating means for generating a wavelet having predefined time domain and frequency domain characteristics;

code generating means, coupled to said wavelet generating means, for generating a group of wavelets of varying polarities in accordance with a predefined code; and

data encoding means for modifying a polarity of said group of wavelets, as a whole, as a function of a bit of said data to be transmitted.

2. The apparatus according to claim 1 wherein said wavelet generating means comprises means for generating the wavelet which includes a Gaussian monocycle.

3. The apparatus according to claim 2 wherein said wavelet has a pulse width in a range from about 100 to about 2000 picoseconds.

4. The apparatus according to claim 3 wherein said wavelet generating means is adapted for generating wavelets in a range from about 10 gigahertz to about 500 megahertz.

5. The apparatus according to claim 2 wherein said wavelet has a pulse width of 1000 picoseconds and frequency of 1 gigahertz.

6. The apparatus according to claim 1, wherein the data to be transmitted is scrambled so as to be uncorrelated.

7. The apparatus according to claim 1, further comprising a whitening encoder for scrambling the data to be transmitted, and providing scrambled data to the data encoding means.

8. The apparatus according to claim 1,

wherein the group of wavelets are made of N consecutive wavelets generated by the wavelet generating means, N being an integer greater than 0, and

wherein the data encoding means modifies the polarities of the N consecutive wavelets as a function of a given data bit.

9. An apparatus fix transmitting data comprising:

a wavelet generator for producing a plurality of wavelets, each of the plurality of wavelets having predefined time domain and frequency domain characteristics;

a code generator for modifying the polarities of N consecutive wavelets individually in accordance with a predefined length-N code; and

a data encoder for modifying polarities of the N consecutive wavelets as a group as a function of one bit of the data to be transmitted,

wherein N is an integer greater than zero.

10. The apparatus according to claim 9, wherein each of the plurality of wavelets includes a Gaussian monocycle.

11. The apparatus according to claim 10, wherein each of the plurality of wavelets has a pulse width in a range from about 100 to about 2000 picoseconds.

12. The apparatus according to claim 10, wherein the wavelet generator produces the plurality of wavelets in a range from about 10 gigahertz to about 500 megahertz in frequency.

13. The apparatus according to claim 9, wherein the data to be transmitted is scrambled so as to be uncorrelated.

14. The apparatus according to claim 9, further comprising a whitening encoder for scrambling the data to be transmitted, and providing scrambled data to the data encoder.

15. The apparatus according to claim 9, wherein the data encoder modifies the polarity of the length-N code.

16. A method for transmitting data comprising:

generating a plurality of wavelets, each having predefined time domain and frequency domain characteristics;

modifying polarities of N consecutive wavelets individually in accordance with a predefined length-N code; and

modifying the polarities of the N consecutive wavelets as a group as a function of one bit of the data to be transmitted,

wherein N is an integer greater than zero.

17. A method according to claim 16, wherein the data to be transmitted is scrambled so as to be uncorrelated.

18. A method according to claim 16, wherein the one bit of the data to be transmitted modifies the polarity of the length-N code.