Method and apparatus for transmitting pilot on multiple antennas
Method and apparatus for transmitting pilot on multiple antennas are disclosed. A wireless transmit/receive unit (WTRU) may transmit a primary dedicated physical control channel (DPCCH) and at least one secondary DPCCH via multiple antennas using different channelization codes. The first eight pilot symbols of the secondary DPCCH may be same as pilot symbols of length eight of the primary DPCCH. The secondary DPCCH may include a same number of pilot bits as the primary DPCCH in a normal mode and in a compressed mode, respectively. The transmit power of the secondary DPCCH may be adjusted based on a ratio of a number of pilot symbols in the primary DPCCH and the secondary DPCCH. When a required transmit power exceeds a maximum allowed transmit power of the WTRU, power scaling may be applied equally to the primary DPCCH and the secondary DPCCH.
1. A method implemented in a wireless transmit/receive unit (WTRU) for transmitting pilot symbols on multiple antennas, the method comprising:
transmitting an uplink primary dedicated physical control channel (DPCCH) and at least one uplink secondary DPCCH (S-DPCCH) via the multiple antennas using different channelization codes, wherein the S-DPCCH carries pilot symbols that are the same as pilot symbols of at least length eight of the primary DPCCH;
transmitting an enhanced dedicated channel (E-DCH) dedicated physical data channel (E-DPDCH), wherein a normalized remaining power margin (NRPM) for an E-DCH transport format combination (E-TFC) selection is performed by taking a primary DPCCH transmit power, an S-DPCCH transmit power, a dedicated physical data channel (DPDCH) transmit power, a high speed dedicated physical control channel (HS-DPCCH) transmit power and an E-DCH dedicated physical control channel (E-DPCCH) transmit power into account;
wherein power scaling is applied equally to the primary DPCCH and the S-DPCCH on a condition that a required transmit power exceeds a maximum allowed transmit power of the WTRU such that a power ratio between the primary DPCCH and the S-DPCCH remains the same after the power scaling; and
wherein, when discontinuous transmission (DTX) is active, the WTRU does not transmit the S-DPCCH in a slot where the WTRU does not transmit the primary DPCCH.
2. The method of claim 1 wherein same number of pilot symbols are transmitted on the S-DPCCH when the WTRU is transmitting in a compressed mode.
3. The method of claim 1 wherein a same total pilot energy ratio is maintained between the primary DPCCH and the S-DPCCH both in a normal mode and in a compressed mode.
4. The method of claim 1 wherein the S-DPCCH transmit power is determined based on a primary DPCCH power target and a gain factor signaled from a higher layer.
5. The method of claim 1 wherein a gain factor for the S-DPCCH is boosted on a condition that E-DCH data is transmitted on a secondary stream.
6. The method of claim 5 wherein an amount of boosting of the gain factor for the S-DPCCH is determined based on a combination of an E-DPDCH gain factor, a scaling factor signaled by a higher layer and a traffic to pilot power ratio signaled by a higher layer.
7. The method of claim 1 wherein the S-DPCCH is continuously transmitted at a different power setting when a second stream is transmitted.
8. The method of claim 1 wherein the S-DPCCH carries ten pilot symbols including two non-frame synchronization word (FSW) symbols.
9. A wireless transmit/receive unit (WTRU) for transmitting pilot symbols on multiple antennas, the WTRU comprising:
a plurality of antennas; and
a circuitry configured to transmit an uplink primary dedicated physical control channel (DPCCH) and at least one uplink secondary DPCCH (S-DPCCH) via the multiple antennas using different channelization codes, wherein the S-DPCCH carries pilot symbols that are the same as pilot symbols of at least length eight of the primary DPCCH;
wherein the circuitry is configured to transmit an enhanced dedicated channel (E-DCH) dedicated physical data channel (E-DPDCH), wherein a normalized remaining power margin (NRPM) for an E-DCH transport format combination (E-TFC) selection is performed by taking a primary DPCCH transmit power, an S-DPCCH transmit power, a dedicated physical data channel (DPDCH) transmit power, a high speed dedicated physical control channel (HS-DPCCH) transmit power and an E-DCH dedicated physical control channel (E-DPCCH) transmit power into account;
wherein power scaling is applied equally to the primary DPCCH and the S-DPCCH on a condition that a required transmit power exceeds a maximum allowed transmit power of the WTRU such that a power ratio between the primary DPCCH and the S-DPCCH remains the same after the power scaling; and
wherein, when discontinuous transmission (DTX) is active, the WTRU does not transmit the S-DPCCH in a slot where the WTRU does not transmit the primary DPCCH.
10. The WTRU of claim 9 wherein same number of pilot symbols are transmitted on the S-DPCCH when the WTRU is transmitting in a compressed mode.
11. The WTRU of claim 9 wherein a same total pilot energy ratio is maintained between the primary DPCCH and the S-DPCCH both in a normal mode and in a compressed mode.
12. The WTRU of claim 9 wherein the S-DPCCH transmit power is determined based on a primary DPCCH power target and a gain factor signaled from a higher layer.
13. The WTRU of claim 9 wherein a gain factor for the S-DPCCH is boosted on a condition that E-DCH data is transmitted on a secondary stream.
14. The WTRU of claim 13 wherein an amount of boosting of the gain factor for the S-DPCCH is determined based on a combination of an E-DPDCH gain factor, a scaling factor signaled by a higher layer and a traffic to pilot power ratio signaled by a higher layer.
15. The WTRU of claim 9 wherein the S-DPCCH is continuously transmitted at a different power setting when a second stream is transmitted.
16. The WTRU of claim 9 wherein the S-DPCCH carries ten pilot symbols including two non-frame synchronization word (FSW) symbols.