# US 2010/0167674 A1 · Integrated circuit, wireless communication unit and method for determining quadrature imbalance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0167674 A1 - Document ID: US20100167674A1 - Status: Published application - Kind: A1 - Application number: 12/600,687 - Filed: 2007-05-31 - Published: 2010-07-01 - Earliest claimed: 2007-05-31 - Assignees: Freescale Semiconductor, Inc. - Inventors: Norman Beamish; Conor O'Keeffe; Patrick Pratt - Web page: https://patentgrep.com/patent/US20100167674A1 ## CPC - H03D 3/009: {Compensating quadrature phase or amplitude imbalances} - H04B 1/30: for homodyne or synchrodyne receivers (demodulator circuits H03D1/22) - H04L 27/0014: {Carrier regulation (of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657)} - H03D: DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers H01S; circuits capable of acting both as modulator and demodulator H03C; details applicable to both modulators and frequency-changers H03C; demodulating pulses H03K9/00; transforming types of pulse modulation H03K11/00; coding, decoding or code conversion, in general H03M; repeater stations H04B7/14; demodulators adapted for AC systems of digital information transmission H04L27/00; synchronous demodulators adapted for colour television H04N9/66) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An integrated circuit comprising processing logic for operably coupling to radio frequency (RF) receiver circuitry arranged to receive a wireless network signal. The receiver circuitry generates in-phase and quadrature digital baseband representations of the wireless network signal. The processing logic determines quadrature (I/Q) imbalance of the RF receiver circuitry based on the in-phase and quadrature digital baseband representations of the wireless network signal. ## Claims ### Claim 1 An integrated circuit comprising processing logic for operably coupling to radio frequency (RF) receiver circuitry arranged to receive a wireless network signal, wherein the receiver circuitry generates in-phase and quadrature digital baseband representations of the wireless network signal and the processing logic determines quadrature (I/Q) imbalance of the RF receiver circuitry based on the in-phase and quadrature digital baseband representations of the wireless network signal, wherein the processing logic is arranged to set the RF receiver circuitry to operate in a very low intermediate frequency (VLIF) mode pursuant to determining quadrature imbalance. ### Claim 2 (depends on 1) The integrated circuit of claim 1 further characterised in that the processing logic is arranged to calibrate the RF receiver circuitry to compensate for quadrature imbalance of the RF receiver circuitry. ### Claim 3 (depends on 1) The integrated circuit of claim 1 further characterised in that the processing logic is arranged to set the RF receiver circuitry to operate in a direct conversion radio (DCR) mode prior to determining quadrature imbalance. ### Claim 4 (depends on 1) The integrated circuit of claim 1 further characterised in that the processing logic is arranged to determine quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a network signal received as part of a power scan operation. ### Claim 5 (depends on 4) The integrated circuit of claim 4 further characterised in that the processing logic is further arranged to synchronise signal timing of a wireless communication unit containing the integrated circuit with a remote base station, wherein the processing logic is arranged to determine quadrature imbalance prior to synchronisation with the remote base station. ### Claim 6 (depends on 1) The integrated circuit of claim 1 further characterised in that the processing logic is arranged to determine quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a network signal received as part of a frequency control channel (FCCh) scan. ### Claim 7 (depends on 6) The integrated circuit of claim 6 further characterised in that the processing logic is arranged to determine quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a frequency correction burst (FCB) within the FCCh. ### Claim 8 A method for determining quadrature (I/O) imbalance within radio frequency (RF) receiver circuitry of a wireless communication unit, the method comprising the steps of: receiving a wireless network signal; generating in-phase and quadrature digital baseband representations of the wireless network signal; determining quadrature (I/O) imbalance of the RF receiver circuitry based on the in-phase and quadrature digital baseband representations of the wireless network signal; and setting the RF receiver circuitry to operate in a very low intermediate frequency (VLIF) mode pursuant to determining quadrature imbalance. ### Claim 9 (depends on 8) The method of claim 8 further comprising calibrating the RF receiver circuitry to compensate for quadrature imbalance of the RF receiver circuitry in response to said determination. ### Claim 10 (depends on 8) The method of claim 8 further comprising setting the RF receiver circuitry to operate in a direct conversion radio (DCR) mode prior to determining quadrature imbalance. ### Claim 11 (depends on 8) The method of claim 8 further comprising determining quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a network signal received as part of a power scan operation. ### Claim 12 (depends on 11) The method of claim 11 further comprising synchronising a wireless communication unit's signal timing with a remote base station subsequent to determining quadrature imbalance. ### Claim 13 (depends on 8) The method of claim 8 further comprising determining quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a network signal received as part of a frequency control channel (FCCh) scan. ### Claim 14 (depends on 13) The method of claim 13 further comprising determining quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a frequency correction burst within the FCCh. ### Claim 15 (depends on 1) A wireless communication unit comprising an integrated circuit according to claim 1. ### Claim 16 (canceled) ### Claim 17 (depends on 15) The wireless communication unit of claim 15, wherein the wireless communication device is one of: a private mobile radio, a cellular phone, a personal digital assistant, a wireless capable laptop computer. ### Claim 18 (depends on 17) The wireless communication unit of claim 17, wherein the cellular phone supports at least one of the following communication formats: Global System for Mobile communications (GSM), general packet radio system (GPRS), enhanced general packet radio system (EGPRS), enhanced GSM (EGSM). ### Claim 19 (depends on 2) The integrated circuit of claim 2 further characterised in that the processing logic is arranged to set the RF receiver circuitry to operate in a direct conversion radio (DCR) mode prior to determining quadrature imbalance. ### Claim 20 (depends on 2) The integrated circuit of claim 2 further characterised in that the processing logic is arranged to determine quadrature imbalance based on measurements of in-phase and quadrature digital baseband representations of a network signal received as part of a power scan operation. ### Claim 21 (depends on 9) The method of claim 9 further comprising setting the RF receiver circuitry to operate in a direct conversion radio (DCR) mode prior to determining quadrature imbalance.