基于时隙捆绑预处理的LTE上行自适应传输

Preprocessing of TTI Bundling for Adaptive Transmission in LTE Uplink

3G长期演进(LTE)上行链路中,基于时隙捆绑(transmission time interval bundling,TTI bundling)技术的IP语音业务(VoIP)可以显著提高小区覆盖范围。目前,一种覆盖增强方案可以使用户在50 ms时延限制下最多传输5捆相同的数据包。然而,由于该方案不能及时处理反馈信号,一旦出现不必要的重传,会导致系统吞吐量降低,并造成用户设备(UE)额外的能量损耗。为此,该文提出了一种基于误块率(BLER)与信噪比(SNR)映射机制的时隙捆绑预处理传输方案,该方案使得UE可以根据信道情况的变化以及期望的性能指标,预先设定传输捆绑数据包的最大值,从而减少了不必要的重传,节省了UE的能量消耗,提高系统的吞吐量。

In order to improve the cell coverage performance, transmission time interval （TTI） bundling technique is employed in long term evolution （LTE） uplink for the voice over internet protocol （VoIP） service. Recently, a coverage-enhanced scheme makes user equipment （UE） transmitting up to five bundles under the same delay budget. However, the coverage-enhanced scheme lacks time for feedback processing, in which the UE transmitting power may be wasted for an unnecessary retransmission. Taking the issue into account, we propose a scheme based on preprocessing of TTI bundling for adaptive transmission in LTE uplink. Our scheme uses block error rate （BLER） versus signal-to-noise ratio （SNR） mapping mechanism to reduce unnecessary retransmission bundles and save UE power consumption, yielding higher throughput.