Method and system for transmitter output power compensation
Aspects of compensating for transmitter output power may comprise sampling an on-chip transmitter circuit temperature at various time instants and determining a feedback temperature compensation value. At least one digital-to-analog converter may be adjusted by utilizing the feedback temperature compensation value, which may correspond to the sampled temperature. The digital-to-analog converter may be an I-component digital-to-analog converter and/or a Q-component digital-to-analog converter. At least a portion of the on-chip transmitter circuit may be characterized to determine power output dependence of the on-chip transmitter circuit on temperature variation of the on-chip transmitter circuit. Based on this characterization, a feedback temperature compensation value that may correspond to the sampled temperature may be used to adjust the digital-to-analog converter. The feedback temperature compensation value may be, for example, from a lookup table or an algorithm.
1. A wireless communication device, comprising:
a sensor circuit configured to sample a temperature of a wireless transmitter of the wireless communication device at a plurality of time instants; and
a digital-to-analog converter configured to receive a digital intermediate frequency (IF) signal of the wireless transmitter, wherein a bias current for the digital-to-analog converter is adjusted via a feedback temperature compensation value corresponding to the sampled temperature at a particular time instant of the plurality of time instants.
2. The wireless communication device according to claim 1 , wherein the digital-to-analog converter comprises an I-component digital-to-analog converter or a Q-component digital-to-analog converter.
3. The wireless communication device according to claim 1 , comprising a lookup table of feedback temperature compensation values that correspond to the sampled temperature.
4. The wireless communication device according to claim 1 , wherein the determined feedback temperature compensation value is calculated using a compensation algorithm that uses at least the following: an initial compensation value, a present temperature, an initial temperature and a scaling factor.
5. The wireless communication device according to claim 4 , wherein one or more default values are assigned to one or more of the following: the initial compensation value, the present temperature, the initial temperature and the scaling factor.
6. The wireless communication device according to claim 4 , wherein an output of the digital-to-analog converter is a desired value when the determined feedback temperature compensation value is equal to the initial compensation value and the sampled temperature is equal to the initial temperature.
7. The wireless communication device according to claim 1 , wherein the mobile wireless communication device has a transmit power specification of approximately 3 dBm.
8. The wireless communication device according to claim 1 , wherein the wireless transmitter comprises a transmitter front end and a baseband processor, and wherein the sensor circuit samples the temperature of the wireless transmitter at the transmitter front end.
9. The wireless communication device according to claim 1 , wherein the wireless communication device is a mobile wireless communication device.
10. The wireless communication device according to claim 9 , wherein the mobile wireless communication device comprises a telephone.
11. The wireless communication device according to claim 1 , wherein the wireless transmitter is part of one or more of the following: a telephone, a walkie-talkie and a personal digital assistant (PDA).
12. The wireless communication device according to claim 1 , wherein the wireless transmitter is part of a router in a home network.
13. The wireless communication device according to claim 1 , wherein the wireless communication device is a mobile wireless communication device that participates in a cellular communication network.
14. The wireless communication device according to claim 1 , wherein the wireless communication device supports time-domain multiple access (TDMA) communications.
15. The wireless communication device according to claim 1 , wherein the wireless communication device supports code division multiple access (CDMA) communications.
16. A method for controlling an output of a wireless transmitter, comprising:
determining a feedback temperature compensation value at a particular one of a plurality of time instants at which a temperature of at least a portion of the wireless transmitter is sampled, where the determined feedback temperature compensation value corresponds to the sampled temperature; and
adjusting a bias current for one or more digital-to-analog converters of the wireless transmitter, where the bias current is adjusted using the determined feedback temperature compensation value, wherein the one or more digital-to-analog converters receive one or more digital intermediate frequency (IF) signals.
17. The method according to claim 16 , wherein the wireless transmitter comprises a transmitter front end and a baseband processor, and wherein the at least a portion of the wireless transmitter that is temperature sampled is the transmitter front end.
18. The method according to claim 16 , wherein the one or more digital-to-analog converters comprise an I-component digital-to-analog converter and a Q-component digital-to-analog converter.
19. The method according to claim 16 , comprising acquiring the determined feedback temperature compensation value from a lookup table of feedback temperature compensation values corresponding to the sampled temperature.
20. The method according to claim 16 , wherein the determined feedback temperature compensation value is calculated using a compensation algorithm, wherein the calculation of the determined feedback temperature compensation value uses at least an initial compensation value, the sampled temperature, an initial temperature and a scaling factor.
21. The method according to claim 20 , comprising assigning a default value to the initial compensation value.
22. The method according to claim 20 , comprising assigning a default value to the initial temperature.
23. The method according to claim 20 , comprising assigning a default value to the scaling factor.
24. The method according to claim 20 , wherein an output of the one or more of the digital-to-analog converters is a desired value when the determined feedback temperature compensation value is equal to the initial compensation value and the sampled temperature is equal to the initial temperature.
25. The method according to claim 16 , wherein the wireless transmitter is part of a mobile wireless communication device.
26. The method according to claim 25 , wherein the mobile wireless communication device comprises a telephone.
27. The method according to claim 16 , wherein the wireless transmitter is part of one or more of the following: a telephone, a walkie-talkie and a personal digital assistant (PDA).
28. The method according to claim 16 , wherein the wireless transmitter is part of a router in a home network.
29. The method according to claim 16 , wherein the wireless transmitter is part of a mobile wireless communication device that participates in a cellular communication network.
30. The method according to claim 16 , wherein the wireless transmitter is part of a wireless communication device that supports time-domain multiple access (TDMA) communications.
31. The method according to claim 16 , wherein the wireless transmitter is part of a wireless communication device that supports code division multiple access (CDMA) communications.
32. A non-transitory machine-readable storage media having stored thereon a program that, when executed by processing circuitry, causes the processing circuitry to:
determine a feedback temperature compensation value at a particular one of a plurality of time instants based at least in part upon a corresponding sampled temperature of at least a portion of a wireless transmitter; and
adjust a bias current for a digital-to-analog converter of the wireless transmitter in response to the determined feedback temperature compensation value, wherein the digital-to-analog converter is configured to receive a digital intermediate frequency (IF) signal.
33. The non-transitory machine-readable storage media of claim 32 , wherein the feedback temperature compensation value is determined from a lookup table of feedback temperature compensation values corresponding to the sampled temperature.
34. The non-transitory machine-readable storage media of claim 32 , wherein the feedback temperature compensation value is determined using a compensation algorithm based at least in part upon the sampled temperature.
35. The non-transitory machine-readable storage media of claim 32 , wherein the compensation algorithm determines the determined feedback temperature compensation value based upon at least an initial compensation value, the sampled temperature, an initial temperature and a scaling factor.
36. The non-transitory machine-readable storage media of claim 32 , wherein the wireless transmitter is part of a wireless communication device.