Spread spectrum microwave overlay with notch filter

• US 5,185,762 A
• Filed: 05/15/1991
• Issued: 02/09/1993
• Est. Priority Date: 05/15/1991
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: SCS Mobilecom, Inc (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/700,788
• Time in Patent Office: 636 Days
• Field of Search: 375/1, 380/33, 380/34
• US Class Current: 370/342
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels

Abstract

A spread spectrum CDMA communications system for communicating data and/or digitized voice between a plurality of users to a plurality of PCN units. The spread spectrum communications system is located within a same geographical region as occupied by an existing microwave system. The spread spectrum can operate without causing undue interference to the microwave system and the microwave system can operate without causing significant interference, less than 1% total users affected, to the PCN system. The spread spectrum CDMA communications system includes a plurality of PCN-base stations and a plurality of PCN units. A PCN-base station has a device for converting the format of the data into a form suitable for communicating over radio waves, a spread spectrum modulator for spread spectrum processing the data, a notch filter, and a transmitter for transmitting the spread spectrum processed converted data from the PCN-base station to a PCN unit. The PCN-base station also has an antenna, and spread spectrum detectors for recovering data communicated from the PCN units. A PCN unit has an antenna, and a detector coupled to the antenna for recovering data communicated from the PCN-base station. The detector includes a spread spectrum demodulator. Also, the PCN unit has a device for converting the format of the data into a form suitable for communicating over radio waves, spread spectrum modulator, an adjustable notch filter and a transmitter.

Claims

1. A spread spectrum CDMA communications system for communicating data, including digitized voice signals, between a plurality of personal-communications network (PCN) units, spread spectrum communications system located within a same geographical region as occupied by a microwave system using a microwave frequency and fixed-service bandwidth, said spread spectrum CDMA communications system comprising:

a plurality of PCN-base stations located within the mobile cellular system for communicating data to the plurality of PCN units, each of said PCN-base stations including,

base means for converting the format of the data for output to communicate over radio waves;

base-product means for spread spectrum processing the data;

base-filter means for notching a spectrum of the spread-spectrum-processed-converted data at the microwave frequency and microwave bandwidth of said microwave system; and

base means for transmitting across the fixed-service bandwidth, the spread-spectrum-processed-converted data from the PCN-base station to a PCN unit;

a plurality of PCN units, each of said PCN units including,

a PCN antenna; and

PCN detection means coupled to said PCN antenna and including PCN-spread-spectrum-processing means, for recovering data communicated from said PCN-base station.

2. The spread spectrum communications system as set forth in claim 1 wherein said PCN detection means includes means for converting the format of the data for output to a user.

3. The spread spectrum communications system as set forth in claim 1 wherein said PCN-spread-spectrum-processing means includes means for storing a local chip code for comparison to signals received for recovering data sent from said PCN-base station to said PCN unit.

4. The spread spectrum communications system as set forth in claim 1 wherein said PCN-spread-spectrum-processing means includes means for synchronizing said PCN-spread-spectrum-processing means to received signals.

5. The spread spectrum communications system as set forth in claim 1 wherein said PCN-spread-spectrum processing means at said PCN-base station includes means for processing data for particular PCN units with a selected chip code.

6. The spread spectrum CDMA communications system as set forth in claim 1 wherein said base-filter means provides more than 10 db attenuation in the fixed-service bandwidth.

7. A spread spectrum CDMA communications system for communicating data, including digitized voice signals, between a plurality of personal-communications network (PCN) units, said spread spectrum communications system located within a same geographical region as occupied by a microwave system using a microwave frequency and fixed-service bandwidth, said spread spectrum CDMA communications system comprising:

a plurality of PCN units, located within a same geographical region as occupied by the microwave system for communicating data to a plurality of users, each of said PCN units including,

PCN-product means for spread spectrum processing the data;

PCN-filter means for notching a spectrum of the spread-spectrum-processed-converted data at the microwave frequency and the microwave bandwidth of said microwave system; and

PCN means for transmitting across the fixed-service bandwidth, the spread-spectrum-processed-converted data from said PCN unit to a PCN-base station;

a PCN-base station including,

a base antenna; and

base detection means including base-spread-spectrum-processing means, for recovering data communicated from said PCN unit.

8. The spread spectrum communications system as set forth in claim 7 wherein said base detection means includes means for converting the format of the data for output to a user.

9. The spread spectrum communications system as set forth in claim 7 wherein said base-spread-spectrum-processing means includes means for storing a local chip code for comparison to signals received for recovering data sent from said PCN-base station to said PCN unit.

10. The spread spectrum communications system as set forth in claim 7 wherein said base-spread-spectrum-processing means includes means for synchronizing said processing means to received signals.

11. The spread spectrum communications system as set forth in claim 7 wherein said base-spread-spectrum-processing means at said PCN-base station includes means for processing data for particular PCN units with a selected-chip code.

12. The spread spectrum communications system as set forth in claim 7 wherein said means for transmitting transmits data in a time division format.

13. The spread spectrum CDMA communications system as set forth in claim 7 wherein said PCN-filter means provides more than 10 dB attenuation in the fixed-service bandwidth.

14. A spread-spectrum transmitter for use with a PCN-system of a spread spectrum CDMA communications system for communicating data, including digitized voice signals between a plurality of personal-communications network (PCN) units, said spread spectrum communications system located within a same geographical region as occupied by a microwave system, said spread-spectrum transmitter comprising:

means for converting the format of the data for output to communicate over radio waves;

product means for spread spectrum processing the data;

filter means for notching a spectrum of the data spread-spectrum-processed-converted at the microwave frequency and microwave bandwidth of said microwave system; and

means for transmitting across a bandwidth of said microwave system, the notched-spread-spectrum-processed-converted data.

15. The spread-spectrum transmitter as set forth in claim 14 wherein said notch means includes a notch filter having band rejection at the plurality of predetermined channels.

16. The spread-spectrum transmitter as set forth in claim 14 wherein said notch means includes an adjustable-notch filter having band rejection at adjustable channels.

17. The spread spectrum transmitter as set forth in claim 15 wherein said filter means provides more than 15 db attenuation in the bandwidth of said microwave system.