Multi-band wireless radiotelephone operative in a plurality of air interface of differing wireless communications systems

• US 5,406,615 A
• Filed: 08/04/1993
• Issued: 04/11/1995
• Est. Priority Date: 08/04/1993
• Status: Expired due to Fees

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Miller, Robert R. II, Russell, Jesse E., Schroeder, Robert E., Partridge, B. Waring III
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Chernoff, Michael B.
• Application Number:
  US08/102,037
• Time in Patent Office: 615 Days
• Field of Search: 455/33.1, 455/33.2, 455/56.1, 379/58, 379/59, 379/60, 379/61, 379/63, 343/749, 343/722, 343/815, 343/702
• US Class Current: 455/552.1
• 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 1/40 Circuits
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• 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 universal wireless radiotelephone communication apparatus is operative in both a first radiotelephone communication system including a first base station having a wide area of coverage, transmitting radiotelephone signals at a first band of frequencies and in a second radiotelephone communication system including a second base station having a localized area of coverage, transmitting radiotelephone signals at a second band of frequencies higher than said first band of frequencies. The second band of frequencies is optimally selected with an offset of less than twice a frequency contained within said first band. The wireless radiotelephone communication apparatus has a common baseband circuitry for operating with both the first base station covering the wide area and with the second base station covering the local area. The common baseband circuitry processing received radiotelephone signals from both base stations and processes signals generated by a user of the handset for transmission to either of these base stations.

Claims

1. A universal wireless radiotelephone communication apparatus operative in a first radiotelephone communication including a first base station having a wide area of coverage, transmitting radiotelephone signals at first band of frequencies and in a second radiotelephone communication system including a second base station having a localized area of coverage, transmitting radiotelephone signals at a second band of frequencies higher than said first band of frequencies with an offset of less than twice a frequency contained within said first band, the wireless radiotelephone communication apparatus comprising:

radio signal reception means for receiving radio signals of two frequencies and including a minimized RF circuit having a single front end circuitry including a filter for rejecting one of the two frequencies and a RF switch connected to bypass the filter and couple radiotelephone signals to the minimized RF circuit;

baseband circuitry connected to the radio signal reception means for processing received radiotelephone signals of both the first and second band of frequencies;

radio signal transmission means connected to receive signals from the baseband circuitry and including a first radio transmission path and including a frequency multiplier interconnecting the baseband circuitry to a second radio transmission path; and

an antenna whose electrical length is a quarter wavelength of a frequency within the first band of frequencies and a three quarter wavelength of a frequency within the third band of frequencies.

2. A universal wireless radiotelephone communication apparatus as claimed in claim 1;

comprising;

stored data processing control included in the wireless radiotelephone communication apparatus;

including;

means for enabling a handoff from the first base station to the second base station, and

means for enabling a handoff from the second base station to the first base station.

3. A universal wireless radiotelephone communication apparatus as claimed in claim 2;

comprising;

means for initializing the wireless radiotelephone communication apparatus for operation with one of the first base station and the second base station.

4. A universal wireless radiotelephone communication apparatus as claimed in claim 2;

comprising;

means for originating calls to one of the first and second base stations.

5. A universal wireless radiotelephone communication system;

comprising;

a first plurality of wide area coverage base stations, including a radio transceiver apparatus and a radiant and receiving antenna, and operative in a first band of frequencies;

a second plurality of local area coverage base stations including a radio transceiver apparatus and a radiant and receiving antenna, operative in a second and third band of frequencies with the second band higher in frequency than the first band of frequencies and the third band of frequencies higher in frequency than the second band of frequency;

the first plurality of wide area coverage base stations and the second plurality of local area coverage base stations all connected to a common land telephone network;

a personal radiotelephone handset for communicating with the first plurality of wide area coverage base stations and the second plurality of local area coverage base stations;

including;

a baseband circuit for processing IF signals for all three bands of RF frequencies;

first minimized RF circuit means connected to the baseband circuit for generating signals for transmission within the first band of frequencies for transmission to the first plurality of wide area coverage base stations;

second minimized RF circuit means connected to the baseband circuit through a frequency tripler for generating signals for transmission within the third band of frequencies for transmission to the second plurality of local area base stations; and

the first and second minimized RF circuit means circuit sharing radio mixers and IF processors in common;

an antenna whose electrical length is a wavelength of a subharmonic frequency within the first band of frequencies and an integer multiple wavelength of a subharmonic frequency within the third band of frequencies;

filter circuitry interconnecting the antenna to the first and second RF circuit means; and

including a reject filter to reject the third band frequencies and a RF switch connected to bypass the reject filter.

6. A universal wireless radiotelephone communication system as claimed in claim 5;

comprising;

stored data processing control included in the wireless radiotelephone communication apparatus;

including;

means for enabling a handoff from the first base station to the second base station, and

means for enabling a handoff from the second base station to the first base station.

7. A universal wireless radiotelephone communication system as claimed in claim 5;

comprising;

means for initializing the wireless radiotelephone communication apparatus for operation with one of the first base station and the second base station.

8. A universal wireless radiotelephone communication system as claimed in claim 5;

comprising;

means for originating calls to one of the first and second base stations.

9. A universal wireless radiotelephone communication system as claimed in claim 5;

comprising;

wherein the antenna has an electrical length of a quarter of a wavelength of a frequency within the first band of frequencies and an integer multiple of a quarter wavelength of a frequency within the third band of frequencies.

10. A universal wireless radiotelephone communication apparatus operative in a first radio telephone communication system including a first base station having a wide area of coverage, transmitting radio signals at a first band of frequencies and in a second radiotelephone communication system including a second base station having a localized area of coverage, transmitting radiotelephone signals at a second band of frequencies higher than said first band of frequencies with an offset of less than twice a frequency contained within said first band;

the wireless radiotelephone communication apparatus comprising;

baseband circuitry for processing received radiotelephone signals and signals generated by a user of the radiotelephone communication apparatus;

a first minimized RF circuit means for generating signals for transmission within the first band of frequencies for transmission to the first base station;

a second minimized RF circuit means of transmission within a third band of frequencies having a frequency three times a frequency within the first band of frequencies for transmission to the second base station; and

the first and second RF circuit means being connected to the baseband circuitry and each sharing in common radio mixers and IF processors for processing radio signals at the first and third band of frequencies;

an antenna whose electrical length is a wavelength of a subharmonic frequency within the first band of frequencies and an integral multiple wavelength of the subharmonic frequency within the third band of frequencies;

filter circuitry interconnecting the antenna to the first and second RF circuit means and including a reject filter to reject the third band of frequencies and a RF switch connected to bypass the reject filter.

11. A universal wireless radiotelephone communication apparatus as claimed in claim 10;

comprising;

stored data processing control included in the wireless radiotelephone communication apparatus;

including;

means for enabling a handoff from the first base station to the second base station, and

means for enabling a handoff from the second base station to the first base station.

12. A universal wireless radiotelephone communication apparatus as claimed in claim 11;

comprising;

means for initializing the wireless radiotelephone communication apparatus for operation with one of the first base station and the second base station.

13. A universal wireless radiotelephone communication apparatus as claimed in claim 11;

comprising;

means for originating calls to one of the first and second base stations.

14. A wireless radiotelephone mobile communications apparatus that operates in a first and second wireless air interface,

the first air interface operating within a first range of frequencies including uplink and downlink frequency bands;

the second air interface operating within at least a second range of frequencies including uplink and downlink frequency bands, one band being greater than a frequency within the first range of frequencies by an integer multiple;

comprising;

radio frequency processing circuitry including

an antenna having a wavelength defined length to operate within both ranges of frequencies;

RF/IF conversion circuitry;

a receive section interconnecting the antenna to the RF/IF conversion circuitry and including a first filtered path for conveying downlink signals at the first and second range of frequencies and including circuitry for rejecting signals at the second range of frequencies, the circuitry for rejecting being controllably switched into the first filtered path;

a first transmit section interconnecting the antenna to the RF/IF conversion circuitry for conveying uplink signals within the first range of frequencies, and including signal splitting circuitry;

a second transmit section connected to the antenna and connected to receive uplink signals from the signal splitting circuitry and including signal multiplication circuitry for increasing the frequency of signals received from the splitting circuitry to the uplink band of the second range of frequency; and

the receive section and first and second transmit sections sharing common mixers and IF processors.

15. A wireless radiotelephone mobile communications apparatus as claimed in claim 14, further comprising:

a duplex filter coupling the receive section and the first transmit section to the antenna.

16. A wireless radiotelephone mobile communications apparatus as claimed in claim 14, further comprising:

the signal multiplication circuitry multiplying by a factor of three.

17. A wireless radiotelephone mobile communications apparatus as claimed in claim 14, further comprising:

power control circuitry for controlling power amplification in the first and second transmit sections.

18. A wireless radiotelephone mobile communications apparatus as claimed in claim 14, further comprising:

the antenna having a length a quarter wavelength of the lower one of the first and second ranges of frequency.