Power controlling method based on DwPTS
First Claim
1. A power control method based on Downlink Piloting Time Slot (DwPTS), comprising an open-loop power control procedure while a terminal is being accessed randomly and a closed-loop power control procedure while communications are being maintained after the terminal is accessed, wherein the open-loop power control procedure while a terminal is being accessed randomly comprises the steps of:
- A. the terminal measuring received DwPTS signal powers transmitted by adjacent base stations during cell searching, sorting the base stations in the order of signal intensity of DwPTS, and determining candidate base stations;
B. the terminal calculating Uplink Piloting Time Slot (UpPTS) transmission power for open-loop power control while the terminal is being accessed according to the base station transmission power broadcasted by a candidate base station, the expected receiving powers and the DwPTS signal power of the base station actually measured by the terminal, and sending an access request to the base station with this transmission power; and
wherein the closed-loop power control procedure after the terminal is accessed comprises the steps of;
C. the base station determining required receiving power, determining actual uplink transmission power required by the base station for closed-loop power control, sending the required receiving power to the terminal by higher layer downlink signaling, and sending the actual uplink transmission power required by the base station to the terminal with a closed-loop power control command;
D. the terminal continuing to measure the actually received DwPTS signal power of the base station, then calculating an uplink transmission power reference value for open-loop power control according to the base station transmission power and the required receiving power; and
E. comparing the calculated uplink transmission power reference value under open-loop power control with the actual uplink transmission power required by the base station under closed-loop control and obtaining a difference, and comparing the difference with a threshold;
if the difference is larger than the threshold, the terminal performing uplink transmission with the power which is equal to the sum of the calculated uplink transmission power reference value for open-loop power control and the threshold, if the difference is not larger than the threshold, the terminal continuing to execute the closed-loop power control command and performing uplink power transmission with the actual transmission power required by the base station for closed-loop power control.
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Accused Products
Abstract
A power-control method base on Downlink Piloting Time Slot (DwPTS) in a mobile communication system. While a terminal is being accessed randomly, the terminal determines the transmitting signal power at Uplink Piloting Time Slot (UpPTS) for open-loop power control by using broadcast information and the measured DwPTS power. While the communications are being maintained, the base station notifies the terminal of the required receiving power, the terminal then calculates the transmitting power for open-loop power control by using the measured DwPTS power, which is taken as the reference transmission power of the uplink channel and compared with the actual transmitting power required by the base station for closed-loop power control; the difference of the comparison is in turn compared with a threshold, if the difference is larger than the threshold, sum of the reference transmission power and the threshold is used as the power to perform transmission, otherwise, the closed-loop power control command is keeping executed. By taking the advantage of the TDD mode in which the uplink and downlink transmissions are, carried out in the same conditions, the method makes full use of open-loop power control which has the merits of being simple and accurate so that complex outer-loop power control is not needed in closed-loop power control, making the RNC simpler and the system more stable. hi addition, since it is the DwPTS power that is measured in the power control, the accuracy of power control is greatly improved.
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Citations
23 Claims
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1. A power control method based on Downlink Piloting Time Slot (DwPTS), comprising an open-loop power control procedure while a terminal is being accessed randomly and a closed-loop power control procedure while communications are being maintained after the terminal is accessed, wherein
the open-loop power control procedure while a terminal is being accessed randomly comprises the steps of: -
A. the terminal measuring received DwPTS signal powers transmitted by adjacent base stations during cell searching, sorting the base stations in the order of signal intensity of DwPTS, and determining candidate base stations;
B. the terminal calculating Uplink Piloting Time Slot (UpPTS) transmission power for open-loop power control while the terminal is being accessed according to the base station transmission power broadcasted by a candidate base station, the expected receiving powers and the DwPTS signal power of the base station actually measured by the terminal, and sending an access request to the base station with this transmission power; and
whereinthe closed-loop power control procedure after the terminal is accessed comprises the steps of;
C. the base station determining required receiving power, determining actual uplink transmission power required by the base station for closed-loop power control, sending the required receiving power to the terminal by higher layer downlink signaling, and sending the actual uplink transmission power required by the base station to the terminal with a closed-loop power control command;
D. the terminal continuing to measure the actually received DwPTS signal power of the base station, then calculating an uplink transmission power reference value for open-loop power control according to the base station transmission power and the required receiving power; and
E. comparing the calculated uplink transmission power reference value under open-loop power control with the actual uplink transmission power required by the base station under closed-loop control and obtaining a difference, and comparing the difference with a threshold;
if the difference is larger than the threshold, the terminal performing uplink transmission with the power which is equal to the sum of the calculated uplink transmission power reference value for open-loop power control and the threshold, if the difference is not larger than the threshold, the terminal continuing to execute the closed-loop power control command and performing uplink power transmission with the actual transmission power required by the base station for closed-loop power control. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A power control method based on DwPTS, comprising an open-loop power control procedure while a terminal is being accessed randomly, wherein
the open-loop power control procedure while a terminal is getting accessed randomly comprises the steps of: -
A. the terminal measuring received DwPTS signal powers transmitted by adjacent base stations during cell searching, sorting the base stations in the order of signal strength of DwPTS, and determining candidate base stations; and
B. the terminal obtaining UpPTS transmission power for open-loop power control while the terminal is getting accessed according to the base station transmission power broadcasted by a candidate base station, the expected receiving power and the DwPTS signal power of the base station actually measured by the terminal, and sending an access request to the base station with this transmission power. - View Dependent Claims (14, 15, 16)
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17. A power control method based on DwPTS, comprising a closed-loop power control procedure while communications are being maintained after the terminal is accessed, wherein
the said closed-loop power control procedure after the terminal is accessed comprising the steps of: -
C. the base station determining the required receiving power, determining actual uplink transmission power required by the base station for closed-loop power control, sending the required receiving power to the terminal by higher layer downlink signaling, and sending the actual uplink transmission power required by the base station to the terminal with a closed-loop power control command;
D. the terminal keeping measuring the actually received DwPTS signal power of the base station, then calculating an uplink transmission power reference value for open-loop power control according to the base station transmission power and the required receiving power; and
E. comparing the calculated uplink transmission power reference value under open-loop power control with the actual uplink transmission power required by the base station for closed-loop control and obtaining a difference, comparing the difference with a threshold;
if the difference is larger than the threshold, the terminal performing uplink transmission with the power which is equal to the sum of the calculated uplink transmission power reference value for open-loop power control and the threshold, if the difference is not larger than the threshold, the terminal continuing to execute the closed-loop power control command and performing uplink power transmission with the actual transmission power required by the base station for closed-loop power control. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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Specification