Inter-modulation distortion reduction in multi-mode wireless communication terminal
A multimode wireless communication terminal that communicates using a first radio access technology (RAT) and a second RAT determines whether the first and second RATs are in an active state, and modifies a maximum transmit power limit of the first RAT based on a voice codec rate of a voice transmission on the second RAT when the first RAT and the second RAT are in the active state concurrently, wherein the second RAT is conducting the voice transmission in the active state. In an alternative embodiment, the limit is modified based on a transmit power status of the second RAT or on a transmission type of the first RAT.
1. A method in a multimode wireless communication mobile terminal that communicates using a first radio access technology (RAT) and a second RAT, the method comprising:
determining whether the multimode wireless communication mobile terminal has been assigned an identifier for simultaneously communicating with the first RAT and the second RAT;
receiving an operational maximum power at which the multimode wireless communication mobile terminal can transmit on the first RAT;
reducing the operational maximum power of the first RAT to a modified maximum transmit power based on a voice codec rate of a voice transmission on the second RAT when the multimode wireless communication mobile terminal has been assigned the identifier for simultaneously communicating with the first RAT and the second RAT; and
transmitting on the first RAT at a transmit power level based on the modified maximum transmit power when the voice transmission is conducted by the second RAT.
2. The method of claim 1 further comprising increasing the modified maximum transmit power of the first RAT when the second RAT conducts the voice transmission using a relatively low voice codec data rate and decreasing the modified maximum transmit power of the first RAT when the second RAT conducts the voice transmission using a relatively high voice codec data rate.
3. The method of claim 1 further comprising modifying an operational maximum power of the second RAT when reducing the operational maximum power of the first RAT.
4. The method of claim 1 , wherein reducing the operational maximum power of the first RAT to a modified maximum transmit power based on the voice codec rate of the voice transmission includes changing the operational maximum power of the first RAT during a silence period of the voice transmission relative to a non-silence period of the voice transmission.
5. The method of claim 4 , wherein the modified maximum transmit power of the first RAT is increased during the silence period of the voice transmission.
6. The method of claim 4 further comprising reducing an operational maximum power of the second RAT during the silence period of the voice transmission.
7. The method of claim 1 , wherein reducing the operational maximum power of the first RAT to a modified maximum transmit power further comprises applying a Maximum Power Reduction (MPR) to reduce the maximum power at which the terminal can transmit to the modified maximum transmit power.
8. The method of claim 7 , wherein reducing the operational maximum power of the first RAT to a modified maximum transmit power further comprises applying an optional additional Maximum Power Reduction (A-MPR) to reduce the maximum power at which the terminal can transmit to the operational maximum power.
9. The method of claim 1 further comprising transmitting uplink control information (UCI) indicating that the first RAT and the second RAT are concurrently active to a base station serving the multimode wireless communication mobile terminal on the first or second RAT in response to determining that the multimode wireless communication mobile terminal is transmitting on the first RAT and the second RAT simultaneously.
10. The method of claim 1 wherein the received operational maximum power is received from a scheduler.
11. A method in a multimode wireless communication mobile terminal that communicates using a first radio access technology (RAT) and a second RAT, the method comprising:
determining whether the multimode wireless communication mobile terminal has been assigned an identifier for simultaneously communicating with the first RAT and the second RAT;
receiving an operational maximum power at which the multimode wireless communication mobile terminal can transmit on the first RAT;
reducing the operational maximum power of the first RAT to a modified maximum transmit power based on either a transmit power status of the second RAT or a transmission type of the first RAT when the multimode wireless communication mobile terminal has been assigned the identifier for simultaneously communicating with both the first RAT and the second RAT; and
transmitting on the first RAT at a transmit power level based on the modified maximum transmit power when the first RAT and the second RAT are in the active state concurrently.
12. The method of claim 11 wherein reducing the operational maximum power of the first RAT to a modified maximum transmit power only occurs over a single slot of a subframe wherein only the single slot includes transmissions in frequency resources that desense the second RAT whereas another slot of the subframe does not include transmissions in frequency resources that desense the second RAT.
13. The method of claim 11 , wherein the transmission type of the transmission over the first RAT is either a control transmission or a data transmission.
14. The method of claim 11 , further comprising increasing the operational maximum power of the first RAT when the transmission type of the first RAT is a control transmission.
15. The method of claim 11 further comprising increasing the operational maximum power of the first RAT and decreasing the operational maximum power of the second RAT when the transmission type of the first RAT is a control transmission.
16. The method of claim 11 further comprising decreasing the operational maximum power of the first RAT and increasing an operational maximum power of the second RAT when the transmission type of the first RAT is a data transmission.
17. The method of claim 11 , wherein the transmit power status of the second RAT is selected from a group comprising: a transmit power headroom of the second RAT; a transmit power level of the second RAT; and an operational maximum power of the second RAT.
18. The method of claim 11 , wherein reducing the operational maximum power of the first RAT to a modified maximum transmit power further comprises applying a Maximum Power Reduction (MPR) to reduce the maximum power at which the terminal can transmit to the operational maximum power.
19. The method of claim 18 , wherein reducing the operational maximum power of the first RAT to a modified maximum transmit power further comprises applying an optional additional Maximum Power Reduction (A-MPR) to reduce the maximum power at which the terminal can transmit to the operational maximum power.