Broadband CDMA overlay system and method

• US 6,011,789 A
• Filed: 10/15/1997
• Issued: 01/04/2000
• Est. Priority Date: 12/05/1990
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Primary Examiner(s): TON, DANG T
• Application Number:
  US08/951,058
• Time in Patent Office: 811 Days
• Field of Search: 370/310, 370/312, 370/313, 370/314, 370/320, 370/321, 370/324, 370/329, 370/335, 370/336, 370/337, 370/342, 370/346, 370/347, 370/350, 370/200, 370/206, 380/34, 380/48, 455/422, 455/11.1, 455/12.1, 455/517, 455/524, 455/525, 455/560, 455/561
• US Class Current: 370/342
• CPC Class Codes: G01S 13/82 wherein continuous-type signals are transmitted
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• CPC Class Codes: H04B 1/7101 with estimation filters
• CPC Class Codes: H04B 1/7102 with transform to frequency domain
• CPC Class Codes: H04B 7/18547 for geolocalisation of a station position fixing by direction or distance determination G01S5/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2631 for broadband transmission
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• 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
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

A spread-spectrum CDMA communications system for communicating data between a plurality of users to a plurality of spread-spectrum units. The spread-spectrum communications system is located within a same geographical region as occupied by an existing FDMA, proposed TDMA or any other mobile-cellular system. The spread-spectrum CDMA communications system includes a plurality of spread-spectrum-base stations and a plurality of spread-spectrum units. A spread-spectrum-base station has a comb filter for notch filtering predetermined channels of the mobile-cellular system, a device for converting the format of the data into a form for communicating over radio waves, a spread-spectrum modulator for spread-spectrum processing the data, and a transmitter for transmitting the spread-spectrum-processed converted data from the spread-spectrum-base station to a spread-spectrum unit. The spread-spectrum-base station also has an antenna, and spread-spectrum detectors for recovering data communicated from the spread-spectrum units. A spread-spectrum unit has an antenna, and a detector, including a spread-spectrum demodulator, coupled to the antenna for recovering data communicated from the spread-spectrum-base station, and the spread-spectrum unit has a spread-spectrum modulator, a transmitter, and a device for converting the format of the data for communicating over radio waves.

Claims

1. A spread-spectrum code division multiple access (CDMA) communications system for communicating data between a plurality of spread-spectrum units, said spread-spectrum CDMA communications system located within a same geographical region as occupied by a mobile-cellular system with each cell of the mobile-cellular system having a cellular bandwidth divided into predetermined channels and guard bands between the predetermined channels, and having cellular units communicating on the predetermined channels, said spread-spectrum CDMA communications system communicating on the predetermined channels, comprising:

a plurality of spread-spectrum-base stations located within the mobile-cellular system for communicating the data to the plurality of spread-spectrum units, each of said spread-spectrum-base stations having base-sector means for sectoring a geographical area covered by said spread-spectrum-base station into at least two sectors, with said spread-spectrum-base station, for each sector, including,

base-converting means for converting the format of the data into a form for output to communicate over radio waves;

base-spread-spectrum-processing means for spread-spectrum-processing the converted data; and

base-transmitting means for transmitting across cellular bandwidth the spread-spectrum-processed-converted data from the spread-spectrum-base station to a spread-spectrum unit as a spread-spectrum signal;

a plurality of spread-spectrum units, each of said spread-spectrum units including,

a unit antenna for receiving the spread-spectrum signal as a received signal; and

a unit-spread-spectrum-detection means, coupled to said unit antenna, for recovering the data in the spread-spectrum signal communicated from said spread-spectrum-base station, said unit-spread-spectrum-detection means including unit-filtering means for filtering the received spread-spectrum signal and unit-spread-spectrum-demodulating means for despreading the received spread-spectrum signal.

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

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

4. The spread-spectrum CDMA communications system as set forth in claim 1 wherein said unit-spread-spectrum-demodulating means includes means for synchronizing said unit-spread-spectrum-detection means to the received signal.

5. The spread-spectrum CDMA communications system as set forth in claim 1 wherein said unit-spread-spectrum-demodulating means at each spread-spectrum-unit includes means for processing the data for particular spread-spectrum units with a selected chip code.

6. The spread-spectrum CDMA communications system as set forth in claim 1 wherein the unit-spread-spectrum-detection means includes a noncoherent detector.

7. The spread-spectrum CDMA communications system as set forth in claim 1 wherein the unit-detection means includes a noncoherent detector.

8. The spread-spectrum CDMA communications system as set forth in claim 6 wherein the unit-spread-spectrum-detection means includes a coherent detector.

9. A spread-spectrum code division multiple access (CDMA) communications system for communicating data between a plurality of spread-spectrum units, said spread-spectrum CDMA communications system located within a same geographical region as occupied by a mobile-cellular system with each cell of the mobile-cellular system having a cellular bandwidth divided into predetermined channels and guard bands between the predetermined channels, and having cellular users communicating on the predetermined channels, said spread-spectrum CDMA communications system communicating on the predetermined channels, comprising:

a plurality of spread-spectrum units, located within a same geographical region as occupied by a mobile-cellular system for communicating the data to a plurality of users, each of aid spread-spectrum units including,

unit-converting means for converting data to a form for output to communicate over radio waves;

unit-spread-spectrum-processing means for spread-spectrum-processing the converted data; and

unit-transmitting means for transmitting across the cellular bandwidth, the spread-spectrum-processed-converted data from said spread-spectrum unit to a spread-spectrum-base station as a spread-spectrum signal;

a spread-spectrum-base station including,

a base antenna for receiving the spread-spectrum signal;

base-sector means coupled to said base antenna for sectoring the received spread-spectrum signal from the predetermined sectors;

base-comb-filtering means for filtering the received spread-spectrum signal at the predetermined channels; and

base-detection means, coupled to said base-sector means, for recovering the data communicated from said spread-spectrum unit, said base-detection means including base-despreading means for demodulating the data from the received spread-spectrum signal.

10. The spread-spectrum CDMA communications system as set forth in claim 9 wherein said base-detection means includes means for converting the format of the data into a form for output to a user.

11. The spread-spectrum CDMA communications system as set forth in claim 9 wherein said base-despreading means includes means for storing a local chip code for comparison to the received spread-spectrum signal for recovering the data sent from said spread-spectrum unit to said spread-spectrum-base station.

12. The spread-spectrum CDMA communications system as set forth in claim 9 wherein said base-despreading means includes means for synchronizing said base-despreading means to the received signal.

13. The spread-spectrum CDMA communications system as set forth in claim 9 wherein said base-despreading means at said spread-spectrum-base station includes means for processing the data for particular spread-spectrum units with a selected-chip code.

14. The spread-spectrum CDMA communications system as set forth in claim 9 wherein said unit-transmitter means transmits the data in a time division format.

15. A spread-spectrum receiver for use with a spread-spectrum-base station of a spread-spectrum code division multiple access (CDMA) communications system for communicating data, between a plurality of spread-spectrum units, said spread-spectrum communications system located within a same geographical region as occupied by a mobile-cellular system with each cell of the mobile-cellular system having a cellular bandwidth divided into a plurality of predetermined channels and guard bands between said plurality of predetermined channels, and having a plurality of cellular users communicating on said plurality of predetermined channels, said spread-spectrum CDMA communications system communicating on said plurality of predetermined channels, said spread-spectrum receiver comprising:

a base antenna;

base-sector means for sectoring a spread-spectrum signal from predetermined sectors;

base-comb-filtering means for notch filtering a received spread-spectrum signal at the plurality of predetermined channels; and

base-detection means for recovering the data in the received spread-spectrum signal communicated from said plurality of spread-spectrum units.