APPARATUS AND METHOD FOR EFFICIENT INTER RADIO ACCESS TECHNOLOGY OPERATION

• US 20070237261A1
• Filed: 04/06/2006
• Published: 10/11/2007
• Est. Priority Date: 04/06/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lindoff, Bengt, Nilsson, Johan
• Granted Patent: US 7,680,215 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04B 1/001 Channel filtering, i.e. selecting a frequency channel within the SDR system multiplexing of multicarrier modulation signals being represented by different frequencies H04L5/06; multiplexing of multicarrier modulation signals H04L5/023
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• 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 36/30 by measured or perceived connection quality data
• 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

An apparatus, and a method performed by the apparatus, including a terminal with a front end receiver and analog filter (AF) operable throughout a bandwidth that is large enough to cover the total bandwidth used by different access technologies that the terminal supports. The terminal is operable to simultaneously extract from the output of a single front end receiver and AF the carrier frequencies and bandwidths of the different access technologies. This permits cell evaluation activity and an ongoing communication session to be conducted simultaneously with different access technologies on different bandwidths within the bandwidth of the analog filter and without interruption of the communication session.

Claims

1. An apparatus, comprising:

an adjustable front-end receiver;

an adjustable analog filter (AF) coupled to the front end receiver;

an analog-to-digital converter (ADC) coupled to the AF;

a plurality of extraction units adapted to receive digital signals from the ADC;

a plurality of evaluation units and a plurality of detection units; and

a first control unit controlling a switching arrangement and fixing the frequency and bandwidths of at least one of the plurality of the extraction units based on signals received from at least one of the plurality of the evaluation units and detection units.

2. The apparatus of claim 1, wherein the front end receiver and AF is adapted to receive frequency signaling throughout a first frequency bandwidth that includes a first carrier frequency to which the front end receiver is tuned;

the ADC adapted to convert an analog signal produced by the front end receiver and AF into a first digital signal within a first frequency bandwidth; and

each of the plurality of extraction units adapted to extract from the first digital signal, a secondary digital signal having a frequency bandwidth equal to or narrower than the first frequency bandwidth, the secondary digital signal being associated with communication in at least one of a plurality of communication systems.

3. The apparatus of claim 2, wherein each of the plurality of detection units is adapted to support a communication session in any of a plurality of communication systems;

and

wherein each of the plurality of evaluation units is operable, while a detection unit is supporting the communication session, to evaluate another signal as a handover candidate.

4. The apparatus of claim 3, wherein the plurality of extraction units are adapted to extract a digital signal that is within a bandwidth which is within the first frequency bandwidth, the plurality of further frequency bandwidths associated with communication in at least one of a plurality of communication systems.

5. The apparatus of claim 4, wherein a first extraction unit is switchably coupled to at least one of the plurality of the detection units for supporting a communication session in one of a plurality of communication systems, and a second extraction unit is switchably coupled to at least one of the plurality of evaluation units for evaluating at least one signal as a handover candidate.

6. The apparatus of claim 2, where the first control unit is adapted to adjust one of the first frequency bandwidth and the first carrier frequency.

7. The apparatus of claim 6, wherein the first control unit controls the adjustment of the front end receiver based on communication quality associated with one of the secondary digital signals.

8. The apparatus of claim 7, wherein the first control unit signals at least one of the front end receiver and the AF to increase the first frequency bandwidth until one of a first and second events occurs, wherein the first event is the communication quality reaching a predetermined quality measure, and wherein the second event is the first frequency bandwidth reaching a predetermined bandwidth value.

9. The apparatus of claim 7, wherein the first control unit signals at least one of the front end receiver and AF to change the carrier frequency until one of first and second events occurs, wherein the first event is the communication quality reaching a predetermined quality measure, and wherein the second event is the carrier frequency reaching a predetermined value.

10. The apparatus of claim 2, where the first control unit is adapted to adjust both of the first frequency bandwidth and the first carrier frequency.

11. The apparatus of claim 2, for use in a mobile wireless communication system.

12. The apparatus of claim 2, wherein each of the plurality of extraction units is adapted to receive signals from any of a WCDMA system, a GSM system and an OFDM-based system.

13. The apparatus of claim 1, further comprising a digital data storage unit coupled to the ADC adapted to store digital signaling output from the ADC.

14. The apparatus of claim 1, further comprising a second control unit coupled between (a) the first control unit and (b) the front end receiver and AF, the second control unit adapted to adjust one of (x) the front end receiver in response to control information from the second control unit, thereby adjusting the center frequency of the bandwidth or (y) the AF in response to control information from the second control unit, thereby adjusting the size of the bandwidth.

15. A communication apparatus for operating in a plurality of communication systems, comprising:

a front end receiver and analog filter (AF) for receiving frequency signaling throughout a first frequency bandwidth that includes a first carrier frequency to which the front end receiver and AF is tuned;

an analog-to-digital converter (ADC) coupled to the front end receiver for converting an analog signal from the front end receiver and AF into a first digital signal that is within a first frequency bandwidth;

a first extraction unit coupled to the ADC for extracting from the first digital signal a second digital signal that corresponds to a second frequency bandwidth which is equal to or within the first frequency bandwidth and which includes a second carrier frequency, the second frequency bandwidth and the second carrier frequency associated with communication in one of the plurality of communication systems; and

a second extraction unit coupled to the ADC, and operable while the first extraction unit is extracting the second digital signal, for extracting from the first digital signal a third digital signal that corresponds to a third frequency bandwidth which is equal to or within the first frequency bandwidth and which includes a third carrier frequency, the third frequency bandwidth and the third carrier frequency associated with communication in one of the plurality of communication systems.

16. The apparatus of claim 15, further comprising a digital storage unit coupled to the ADC for storing the first digital signal therein and wherein the first and second extraction units receive the first digital signal from the digital storage unit while the receiver is idle.

17. The apparatus of claim 16, further comprising:

first and second evaluation units switchably coupled to the first and second extraction units, the first and second evaluation units adapted to simultaneously evaluate signals as handover candidates while the receiver is idle; and

first and second detection units switchably coupled to the first and second extraction units, the first and second detection units operable to support a communication session with one of the communication systems while the front end receiver is operating.

18. The apparatus of claim 17, further comprising:

a first control unit controlling a switching arrangement operable to switchably couple at least one of the plurality of extraction units to the at least one of the plurality of detection units and at least one of the plurality of evaluation units;

wherein at least one of the coupled detection units is operable to support a communication session with one of the communication systems while the front end receiver and AF is operating; and

wherein at least one of the coupled evaluation units is operable, while the front end receiver and AF is operating and the detection unit is supporting the communication session, to evaluate other signals as handover candidates.

19. The apparatus of claim 18, further comprising a second control unit controlling the front end receiver and AF, the front end receiver and AF responsive to the second control unit for adjusting one of the first bandwidth and the first carrier frequency.

20. The apparatus of claim 19, wherein the second control unit controls the adjusting by the front end receiver and AF based on communication quality associated with one of the second and third carrier frequencies.

21. The apparatus of claim 15, wherein each of the plurality of extraction units is adapted to receive signals from any of a WCDMA system, a GSM system and an OFDM-based system.

22. A method of operating in a plurality of communication systems, comprising:

receiving frequency signaling throughout a first frequency bandwidth that includes a first carrier frequency;

converting an analog signal produced in the receiving step into a first digital signal that corresponds to the first frequency bandwidth;

extracting from the first digital signal a secondary digital signal that is within a secondary frequency bandwidth which is equal to or within the first frequency bandwidth and which includes a secondary carrier frequency, the secondary frequency bandwidth and the secondary carrier frequency associated with communication in a first of a plurality of communication systems; and

while performing the step of extracting the secondary digital signal, extracting from the first digital signal at least one additional secondary digital signal that corresponds to a frequency bandwidth which is also equal to or within the first frequency bandwidth and which also includes a carrier frequency, the at least one additional secondary frequency bandwidth and its corresponding carrier frequency associated with communication in a communication system similar to or different from that used the secondary digital signal.

23. The method of claim 22, including storing the first digital signal, the extracting steps including extracting the secondary digital signal and the at least one additional secondary digital signal from the stored first digital signal after completion of the receiving step.

24. The method of claim 22, wherein the receiving step includes adjusting one of the first bandwidth and the first carrier frequency based on communication quality associated with one of the secondary carrier frequencies.

25. The method of claim 22, wherein the receiving step includes adjusting one of the first bandwidth and the first carrier frequency based on communication quality associated with one of the secondary carrier frequencies.

26. The method of claim 22, including performing the adjusting step at points in time that occur one from the group of periodically and whenever a handover occurs.

27. A method of operating in a plurality of communication systems, comprising:

receiving frequency signaling throughout a first frequency bandwidth that includes a first carrier frequency;

converting an analog signal produced in the receiving step into a first digital signal that corresponds to the first frequency bandwidth;

extracting from the first digital signal a second digital signal that is within a second frequency bandwidth which is within the first frequency bandwidth and which includes a second carrier frequency, the second frequency bandwidth and the second carrier frequency associated with communication in one of the communication systems; and

while performing the step of extracting the second digital signal, extracting from the first digital signal a third digital signal that corresponds to a third frequency bandwidth which is within the first frequency bandwidth and which includes a third carrier frequency, the third frequency bandwidth and the third carrier frequency associated with communication in another of the cellular communication systems.

28. The method of claim 27, including storing the first digital signal, the extracting steps including extracting the second and third digital signals from the stored first digital signal after completion of the receiving step.

29. The method of claim 27, wherein the receiving step includes adjusting one of the first bandwidth and the first carrier frequency based on communication quality associated with one of the second and third carrier frequencies.

30. The method of claim 27, wherein the receiving step includes adjusting one of the first bandwidth and the first carrier frequency based on communication quality associated with one of the second and third carrier frequencies.

31. The method of claim 27, including performing the adjusting step at points in time that occur one of periodically and whenever a handover occurs.