Apparatus and method for efficient inter radio access technology operation

• US 7,680,215 B2
• Filed: 04/06/2006
• Issued: 03/16/2010
• Est. Priority Date: 04/06/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lindoff, Bengt, Nilsson, Johan
• Primary Examiner(s): Liu; Shuwang
• Assistant Examiner(s): MCKIE, GINA M
• Application Number:
  US11/278,878
• Publication Number:
  US 20070237261A1
• Time in Patent Office: 1,440 Days
• Field of Search: None
• 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 adjustable front end receiver, wherein the adjustable front end receiver and adjustable AF are adapted to receive frequency signaling throughout a first frequency bandwidth that includes a first carrier frequency to which the adjustable front end receiver is tuned;

an analog-to-digital converter (ADC) coupled to the adjustable AF, wherein the ADC is adapted to convert an analog signal produced by the adjustable front end receiver and adjustable AF into a first digital signal within the first frequency bandwidth;

a plurality of extraction units adapted to receive the first digital signal from the ADC, 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;

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

a first control unit controlling a switching arrangement and fixing the frequencies 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;

wherein each of the plurality of detection units is adapted to support a communication session in any of 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.

2. The apparatus of claim 1, 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 the 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.

3. An apparatus, comprising:

an adjustable front-end receiver;

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

an analog-to-digital converter (ADC) coupled to the adjustable 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 frequencies and bandwidths of at least one of the plurality of extraction units based on signals received from at least one of the plurality of evaluation units and detection units;

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

4. The apparatus of claim 3, further comprising:

a communication apparatus for operating in a plurality of communication systems, comprising;

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

an analog-to-digital converter (ADC) coupled to the front end receiver for converting an analog signal from the adjustable front end receiver and adjustable 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;

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;

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.

5. The apparatus of claim 4, 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 adjustable front end receiver and adjustable AF is operating; and

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

6. The apparatus of claim 5, further comprising a second control unit controlling the adjustable front end receiver and adjustable AF, the adjustable front end receiver and adjustable AF responsive to the second control unit for adjusting at least one of the first bandwidth and the first carrier frequency.

7. The apparatus of claim 6, wherein the second control unit controls the adjusting by the adjustable front end receiver and adjustable AF based on communication quality associated with at least one of the second and third carrier frequencies.