Method and system for calibrating a multi-mode, multi-standard transmitter and receiver
Methods and systems for calibrating a multi-mode, multi-standard transmitter and receiver are disclosed. Aspects of the method may include configuring calibration paths in a transceiver on a chip including a plurality of Tx and Rx paths. IP2 distortion may be calibrated for the Rx paths utilizing a phase locked loops in the chip and the configurable calibration paths. Local oscillator leakage, Rx path DC offset and RSSI, Tx and Rx I and Q mismatch, and Tx and Rx path filters may be calibrated utilizing the plurality of configurable calibration paths. Cutoff frequency of the filters in the Tx and Rx paths may be calibrated. Blocker signals may be mitigated by calibrating amplifier gains in the Rx paths. The calibration paths may include an envelope detector. Local oscillator leakage and I and Q mismatch may be mitigated utilizing pre-distortion generated by an on-chip digital signal processor in the Tx paths.
1. A method for processing signals, the method comprising:
in a multi-band, multi-standard wireless transceiver comprising a transmitter (Tx) path, a receiver (Rx) path, and a plurality of calibration paths between said Tx path and said Rx path:
sending two test tones of different frequencies from said Tx path to said Rx path over a first one of said plurality of calibration paths, wherein said first one of said plurality of calibration paths is coupled to said Tx path between an output of a mixer and an input of a power amplifier and coupled to said Rx path between an output of an antenna and an input of a low noise amplifier;
measuring a processed result of said two test tones at an output of said Rx path;
adjusting a mixer in said Rx path based on said processed result to calibrate for second-order intercept point distortion; and
before sending said two test tones of different frequencies from said Tx path to said Rx path over said first one of said calibration paths, calibrating a filter in said Tx path using a second one of said plurality of calibration paths and calibrating a filter in said Rx path using a third one of said plurality of calibration paths.
2. The method according to claim 1 , comprising calibrating local oscillator leakage using said plurality of calibration paths.
3. The method according to claim 1 , comprising calibrating one or more amplifier gains in said Rx path to mitigate blocker signals.
4. The method according to claim 1 , comprising calibrating a DC offset in said Rx path using said plurality of calibration paths.
5. The method according to claim 1 , comprising calibrating received signal strength for said Rx path using said plurality of calibration paths.
6. The method according to claim 1 , wherein said second one of said plurality of calibration paths is coupled to said Tx path after an output of said filter in said Tx path and is coupled to said Rx path after an output of said filter in said Rx path.
7. The method according to claim t, wherein calibrating said filter in said Tx path comprises calibrating a cutoff frequency of said filter in said Tx path.
8. The method according to claim 1 , wherein one or more of said calibration paths comprise an envelope detector.
9. The method according to claim 1 , comprising mitigating local oscillator leakage using pre-distortion generated by an on-chip digital signal processor in said Tx path.
10. A system for processing signals, the system comprising:
one or more circuits for use in a multi-band, multi-standard wireless transceiver comprising a transmitter (Tx) path, a receiver (Rx) path, and a plurality of calibration paths between said Tx path and said Rx path, wherein said one or more circuits are configured to:
send two test tones of different frequencies from said Tx path to said Rx path over a first one of said plurality of calibration paths, wherein said first one of said plurality of calibration paths is coupled to said Tx path between an output of a mixer and an input of a power amplifier and coupled to said Rx path between an output of an antenna and an input of a low noise amplifier;
measure a processed result of said two test tones at an output of said Rx path;
adjust a mixer in said Rx path based on said processed result to calibrate for second-order intercept point distortion, and
before sending said two test tones of different frequencies from said Tx path to said Rx path over said first one of said calibration paths, calibrate a filter in said Tx path using a second one of said plurality of calibration paths and calibrate a filter in said Rx path using a third one of said plurality of calibration paths.
11. The system according to claim 10 , wherein said one or more circuits arc configured to calibrate local oscillator leakage using said plurality of calibration paths.
12. The system according to claim 10 , wherein said one or more circuits are configured to calibrate one or more amplifier gains in said Rx path to mitigate blocker signals.
13. The system according to claim 10 , wherein said one or more circuits are configured to calibrate a DC offset in said Rx path using said plurality of calibration paths.
14. The system according to claim 10 , wherein said one or more circuits are configured to calibrate received signal strength for said RX path using said plurality of calibration paths.
15. The system according to claim 10 , wherein said second one of said plurality of calibration paths is coupled to said Tx path after an output of said filter in said Tx path and is coupled to said Rx path after an output of said filter in said Rx path.
16. The system according to claim 10 , wherein said one or more circuits are configured to calibrate a cutoff frequency of said filter in said Tx path.
17. The system according to claim 10 , wherein one or more of said plurality of calibration paths comprise an envelope detector.
18. The system according to claim 10 , wherein said one or more circuits are configured to mitigate local oscillator leakage using pre-distortion generated by an on-chip digital signal processor in said Tx path.
19. The system according to claim 10 , wherein the second-order intercept point distortion is caused by leakage from said Tx path.
20. A method comprising:
sending two test tones of different frequencies over a first calibration path coupled to a transmitter (Tx) path between an output of a mixer and an input of a power amplifier and coupled to a receiver (Rx) path between an output of an antenna and an input of a low noise amplifier;
measuring a processed result of said two test tones at an output of said Rx path;
adjusting a mixer in said Rx path based on said processed result to calibrate for second-order intercept point distortion caused by leakage from said Tx path; and
before sending said two test tones of different frequencies from said Tx path to said Rx path over said first calibration path, calibrating a filter in said Tx path using a second calibration path and calibrating a filter in said Rx path using a third calibration path.