Outer-loop power control method

Abstract

The present invention discloses an outer-loop power control method comprising presetting the duration of the adjustment period and the target block error ratio (BLER)of outer-loop power control; calculating, on the real-time basis, the number of accumulated absolute error blocks of transmission data blocks during the current outer-loop power control adjustment period, and directly up-regulating the target value of signal to interference ratio (SIR Target) and ending the current outer-loop power control adjustment period and starting the next outer-loop power control adjustment period if the number of accumulated absolute error blocks is greater than the preset direct up-regulation threshold; calculating the BLER mean value within the outer-loop power control adjustment period when any outer-loop power control adjustment period reaches to the duration and adjusting SIR Target based on the BLER mean value and preset target BLER. SIR Target can be adjusted in time and the convergence speed thereof can be improved through the method disclosed in the invention.

Description

technical field [0001] The invention relates to a power control method in a communication system, in particular to an outer loop power control method. Background technique [0002] In Time Division Multiplexing - Synchronous Code Division Multiple Access (TD-SCDMA) system, the open-loop power control is used to determine the user's initial transmit power, and the closed-loop power control is estimated by the measurement of the signal-to-interference ratio (SIR) and the SIR target Value (SIR Target), adjust the size of the transmit power, and complete the main process of power control. [0003] In different multipath environments, the SIR Target used for closed-loop power control changes, and it is necessary to adjust the SIR Target of the inner-loop power control according to the block error rate (BLER) of the received signal, so that the system can always use the minimum power To meet the requirements of communication quality. The process of adjusting the SIR Target accor...

AI Technical Summary

Problems solved by technology

This outer loop power control method adopts a periodic and fixed-step adjustment method for the SIR Target. Interference area, etc.), if the outer loop power control adjustment period is in progress, timely SIR Target adjustment cannot be achieved, and the SIR Target after the open loop will converge slowly

[0006] For Wideband Code Division Multiple Access (WCDMA) systems, the inner loop power control frequency is very high, 1500 Hz, so the WCDMA outer loop power control period is very short, and the above-mentioned problem of untimely adjustment of the outer loop will not occur. However, for the TD-SCDMA system, the inner loop power control frequency is relatively low, only 200Hz, so the outer loop power control cycle cannot be too short, so there must be the above-mentioned problems of untimely adjustment of SIR Target and slow convergence speed

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