LTE系统中一种改进的CQI修正算法的设计

在LTE系统下行链路中,由于无线信道的随机变化特性,使得终端测量上报的信道质量指示CQI值不准确,最终影响数据的传输质量,所以必须对测量上报的CQI值进行修正。然而原有的CQI修正算法存在一定的缺陷,介于此,本文在原有算法的基础上提出了一种改进的CQI修正算法,可实现随着信道的变化,基站对终端测量上报的CQI值进行修正,从而自适应的选择合适的调制编码方式,以最大化地利用无线信道的传输能力。本文最终在LTE下行链路平台上进行仿真,结果表明,当终端在高速信道模型ETU300下运动时,在采用真实噪声功率估计的情况下,改进后的算法相比于原算法能获得更高的性能增益。

An improved modified CQI algorithm design in LTE system

In the downlink of LTE system, due to the random variation characteristics of the wireless channel, making the channel quality indicator (CQI) value through the terminal measurement report is not accurate,which will ultimately affect the quality of data transmission,so wo must modify the CQI value. But the original modified CQI algorithm has some defects, In response to these problems, this paper presents a modified CQI algorithm,which the base station can modify the CQI value through the terminal measurement report with the change of channel,then it can adaptively select the appropriate modulation and coding scheme, maximize using the transmission capacity of the wireless channel. This paper eventually simulates in the downlink platform of LTE system, the simulation results show that, when the terminal moving in the high-speed channel model ETU300, in the case of real noise power estimation, compared with the original algorithm,the improved algorithm can obtain higher performance gain.