Transmit power control for physical random access channels
The invention relates to methods for adjusting the transmit power utilized by a mobile terminal for uplink transmissions, and to methods for adjusting the transmit power used by a mobile terminal for one or more RACH procedures. The invention is also providing apparatus and system for performing these methods, and computer readable media the instructions of which cause the apparatus and system to perform the methods described herein. In order to allow for adjusting the transmit power of uplink transmissions on uplink component carriers, the invention suggests introducing a power scaling for uplink PRACH transmissions performing RACH procedures on an uplink component carrier. The power scaling is proposed on the basis of a prioritization among multiple uplink transmissions or on the basis of the uplink component carriers on which RACH procedures are performed.
1. An integrated circuitry, comprising:
adjusting circuitry, which, in operation, controls:
determining power of first physical random access channel (PRACH) transmission on a first component carrier, and determining power of second PRACH transmission on a second component carrier; and
responsive to that the first PRACH transmission in a first subframe overlaps in a time domain with the second PRACH transmission in a second subframe having a different start time from the first subframe and that total power of the first PRACH transmission and the second PRACH transmission exceeds a configured transmission power value (P MAX ), adjusting the power of the second PRACH transmission in the second subframe so that the total power at an overlapped portion between the first PRACH transmission in the first subframe and the second PRACH transmission in the second subframe does not exceed P MAX ; and
transmission circuitry, which, in operation, controls transmitting a first random access preamble in the first subframe on the first component carrier at the power of the first PRACH transmission, and transmitting a second random access preamble in the second subframe on the second component carrier at the power of the second PRACH transmission,
wherein the first component carrier is a Primary Cell and the second component carrier is another Cell, and
wherein the Primary Cell belongs to a first timing advance group (TAG) and the another Cell belongs to a second TAG different from the first TAG.
2. The integrated circuitry according to claim 1 , wherein the adjusting circuitry, in operation, controls adjusting the power of the second PRACH transmission by reducing the power of the second PRACH transmission.
3. The integrated circuitry according to claim 1 , wherein the adjusting circuitry, in operation, controls adjusting the power of the second PRACH transmission per subframe.
4. The integrated circuitry according to claim 1 , wherein, when physical uplink shared channel (PUSCH) transmission is carried out simultaneously with the first PRACH transmission, and
the adjusting circuitry, in operation, controls determining and adjusting power of the PUSCH transmission so that total power of the first PRACH transmission and the PUSCH transmission does not exceed P MAX .
5. The integrated circuitry according to claim 1 , wherein the power of the first PRACH transmission in the first subframe is unadjusted.
6. The integrated circuitry according to claim 1 , wherein the second PRACH transmission is initiated by a physical downlink control channel (PDCCH) order.
7. The integrated circuitry according to claim 1 , wherein the adjusting circuitry, in operation, controls adjusting power of physical uplink shared channel (PUSCH) transmission, power of physical uplink control channel (PUCCH) transmission, the power of the second PRACH transmission, and the power of the first PRACH transmission, in this order.