Multi-band, multi-mode spread-spectrum communication system

• US 6,389,059 B1
• Filed: 03/23/1999
• Issued: 05/14/2002
• Est. Priority Date: 05/13/1991
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Xircom Wireless Incorporated (Intel Corporation)
• Inventors: Dixon, Robert C., Smith, Douglas G., Vanderpool, Jeffrey S.
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US09/275,067
• Time in Patent Office: 1,148 Days
• Field of Search: 345/130, 345/140, 345/141, 345/146, 345/147, 370/335, 370/342, 370/338, 455/58.2, 455/422, 455/436, 455/437, 455/438, 455/462, 455/463, 455/464, 455/465, 455/525, 455/560, 455/426
• US Class Current: 375/141
• CPC Class Codes: G10L 19/012 Comfort noise or silence coding
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/006 using switches for selecting the desired band H04B1/0057 takes precedence
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/7071 with dynamic control of receiver resources
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04B 7/2634 for channel frequency control
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A technique for spread-spectrum communication which uses more than one mode and more than one frequency band. Selectable modes include narrowband mode and spread-spectrum mode, or cellular mode and microcellular mode. Selectable frequency bands include both licensed and unlicensed frequency bands, particularly frequency bands including the 902-928 MHz, 1850-1990 MHz, and 2.4-2.4835 GHz frequency bands. Spread-spectrum communication channels are 10 MHz or less in width. The frequency band onto which spread-spectrum signals are encoded may be changed upon a change in environment or other control trigger, such as establishment or de-establishment of communication with a private access network.

Claims

1. A method of communication, comprising the steps of:

selecting a first carrier frequency within a first frequency band associated with a first multiple access network;

transmitting a first spread spectrum signal modulated onto the first carrier frequency from a mobile transceiver to the first multiple access network;

receiving a second spread spectrum signal modulated onto the first carrier frequency at the mobile transceiver from the first multiple access network;

selecting a second carrier frequency within a second frequency band different from the first frequency band and associated with a second multiple access network;

transmitting a third spread spectrum signal modulated onto the second carrier frequency from the mobile transceiver to the second multiple access network; and

receiving a fourth spread spectrum signal modulated onto the second carrier frequency at the mobile transceiver from the second multiple access network.

2. A method as in claim 1 wherein the first and second spread spectrum signals are transmitted using time division multiple access.

3. A method as in claim 1 wherein the first frequency band is within a licensed frequency band and the first multiple access network is a public access network.

4. A methods as in claim 3 wherein the second frequency band is, at least partially, outside the licensed frequency band and the second multiple access network is a private access network.

5. A method as in claim 4 wherein the private access network is a microcellular system.

6. A method as in claim 1 further comprising the steps of:

receiving the first spread spectrum signal at a destination station;

monitoring a spread spectrum signal-to-noise ratio of the first spread spectrum signal received at the destination station; and

switching from the first carrier frequency to the second carrier frequency in response to the spread spectrum signal-to-noise ratio.

7. A method as in claim 1 further comprising the step of switching from the first carrier frequency to the second carrier frequency in response to a failure to establish communication with a destination station.

8. A method as in claim 7 wherein the first frequency band is within a frequency range selected from a group of frequency ranges consisting of about 902-928 megahertz, 1850-1990 megahertz, and 2400-2483.5 megahertz.

9. An apparatus for mobile wireless communication, comprising:

a transmission circuit having a first transmission mode for transmitting spread spectrum data over a first carrier frequency within a first frequency band to a first multiple access network and a second transmission mode for transmitting spread spectrum data over a second carrier frequency within a second frequency band different from the first frequency band to a second multiple access network;

a reception circuit having a first reception mode for receiving spread spectrum data over the first carrier frequency from the first multiple access network and a second reception mode for receiving spread spectrum data over the second carrier frequency from the second multiple access network; and

a control circuit coupled to said transmission circuit and to said reception circuit and programmed for switching said transmission circuit between the first and second transmission modes and switching said reception circuit between the first and second reception.

10. An apparatus as in claim 9 wherein said transmission circuit is capable of transmitting the spread spectrum data using time division multiple access.

11. An apparatus as in claim 9 wherein the first frequency band is in a licensed frequency band and the first multiple access network is a public access network.

12. An apparatus as in claim 11 wherein the second frequency band is in an unlicensed frequency band and the second multiple access network is a microcellular private access network.

13. An apparatus as in claim 11 wherein the first carrier frequency has a bandwidth of 10 megahertz or less.

14. An apparatus as in claim 9 wherein said control circuit is programmed for switching said transmission circuit between the first and second transmission modes in response to a spread spectrum signal-to-noise ratio.

15. An apparatus as in claim 9 wherein the first and second carrier frequencies are selected from ranges consisting of about 920-928, 1850-1990, and 2400-2483.5 megahertz.

16. An apparatus as in claim 12 wherein said transmission circuit, while in the second transmission mode, transmits the spread spectrum data to the microcellular private access network at a power level of about 0.1 Watt.

17. A method for wireless communication, comprising the steps of:

tuning a transceiver to a first carrier frequency band associated with a first multiple access network;

transmitting a first spread spectrum signal over the first carrier frequency band from the transceiver to a base station in the first multiple access network;

tuning the transceiver to a second carrier frequency band different from the first carrier frequency and associated with a second multiple access network; and

transmitting a second spread spectrum signal over the second carrier frequency band from the transceiver to a base station in the second multiple access network.

18. The method as claimed in claim 17, further comprising the step of receiving a third spread spectrum signal over the first carrier frequency band at the transceiver from the base station in the first multiple access network.

19. The method as claimed in claim 17, wherein the steps of transmitting a first spread spectrum signal and transmitting a second spread spectrum signal include transmitting the first and second spread spectrum signals using time division multiple access.

20. The method as claimed in claim 17, wherein the step of tuning a transceiver to a first carrier frequency band includes tuning the transceiver to the first carrier frequency band within a licensed carrier frequency band associated with a public access network.

21. The method as claimed in claim 20, wherein the step of transmitting a first spread spectrum signal further includes the step of modulating the first spread spectrum signal over the first carrier frequency band having a bandwidth of about 10 megahertz or less.

22. The method as claimed in claim 20, wherein the step of tuning the transceiver to a second carrier frequency band includes tuning the transceiver to an unlicensed carrier frequency band associated with a microcellular private access network.

23. The method as claimed in claim 22, wherein the step of transmitting a second spread spectrum signal further includes transmitting the second spread spectrum signal at a power level of about 0.1 Watt.

24. The method as claimed in claim 17, further comprising the steps of:

receiving the first spread spectrum signal at a destination station;

monitoring a signal-to-noise ratio of the first spread spectrum signal at the destination station; and

tuning the transceiver from the first carrier frequency band to the second carrier frequency band in response to the signal-to-noise ratio.

25. The method as claimed in claim 24, further comprising the step of tuning the transceiver from the first carrier frequency band to the second carrier frequency band in response to a failure to establish communication with the destination station.

26. The method as claimed in claim 17, wherein the step of tuning a transceiver to a first carrier frequency band includes selecting the first carrier frequency band from a range consisting of about 902-928 megahertz, 1850-1990 megahertz, and 2400-2483.5 megahertz.