Power control in orthogonal sub-channels in wireless communications
A method and apparatus for power control in a wireless communication involves establishing at least two orthogonal sub-channels within a channel for communication and controlling transmitted power in each sub-channel independently.
1. A method for use in a base station, the method comprising:
establishing in-phase and quadrature sub-channels in a same timeslot on a first downlink channel, wherein a first wireless transmit/receive unit (WTRU) is assigned to a first sub-channel of the in-phase and quadrature sub-channels and a second WTRU is assigned to a second sub-channel of the in-phase and quadrature sub-channels in the same timeslot;
controlling transmit power for active transmissions to the first WTRU and the second WTRU in each sub-channel independently;
transmitting information for the first WTRU on the first sub-channel and information for the second WTRU on the second sub-channel;
monitoring channel conditions on the first downlink channel; and
assigning the second WTRU from the second sub-channel to a second downlink channel based on the monitored channel conditions.
2. The method of claim 1 , wherein the controlling transmit power is performed adaptively.
3. The method of claim 2 , wherein the controlling transmit power is performed adaptively using criteria including at least one of a signal power level, a noise level, and an interference level.
4. The method as in claim 1 , the method further comprising:
assigning a third WTRU to the second sub-channel; and
transmitting information for the first WTRU on the first sub-channel and information for the third WTRU on the second sub-channel.
5. The method of claim 1 , wherein the first downlink channel and the second downlink channel are Packet Data Channels (PDCHs).
6. A base station, comprising:
a processor and transceiver configured to:
establish in-phase and quadrature sub-channels in a same time slot on a first downlink channel, wherein a first wireless transmit/receive unit (WTRU) is assigned to a first sub-channel of the in-phase and quadrature sub-channels and a second WTRU is assigned to a second sub-channel of the in-phase and quadrature sub-channels;
control transmit power for active transmissions to the first WTRU and the second WTRU of the sub-channels independently;
transmit information for the first WTRU on the first sub-channel and information for the second WTRU on the second sub-channel;
monitor channel conditions on the first downlink channel; and
assign the second WTRU from the second sub-channel to a second downlink channel based on the monitored channel conditions.
7. The base station of claim 6 , wherein the processor and transceiver are further configured to perform the control of the transmit power adaptively.
8. The base station of claim 7 , wherein the processor and transceiver are configured to perform the control of the transmit power using criteria including at least one of a signal power level, a noise level, and an interference level.
9. The base station of claim 6 , wherein the processor and transceiver are further configured to:
assign a third WTRU to the second sub-channel; and
transmit information for the first WTRU on the first sub-channel and information for the third WTRU on the second sub-channel.
10. The base station of claim 6 , wherein the first downlink channel and the second downlink channel are Packet Data Channels (PDCHs).
11. A wireless transmit/receive unit (WTRU) comprising:
a processor configured to receive downlink transmissions from a base station via one of in-phase and quadrature sub-channels on a downlink channel, wherein the WTRU is assigned to a first sub-channel of the in-phase and quadrature sub-channels and another WTRU is assigned to a second sub-channel of the in-phase and quadrature sub-channels in the same timeslot on the downlink channel, wherein a transmit power for active transmissions to the WTRU and another WTRU on each of the in-phase and quadrature sub-channels is controlled independently.
12. The WTRU of claim 11 , wherein the transmit power on each of the sub-channels is controlled adaptively.
13. The WTRU of claim 11 , wherein the transmit power on each of the sub-channels is controlled adaptively using criteria including at least one of a signal power level, a noise level, and an interference level.
14. The WTRU of claim 11 , wherein the downlink channel is a Packet Data Channel (PDCH).