LTE-A系统中ROHC协议O模式的研究与实现

Research and Realization of O Mode of ROHC Protocol in LTE-A System

LTE-A系统中采用了全IP承载,随着数据流向下层的不断传输,互联网各层协议封装的报头信息越来越大,当传输的数据包负载部分较小时,报头部分所占比例较大,降低了通信链路中带宽的利用率.为了提高系统吞吐率,在OAI平台上对LTE-A系统采用了鲁棒性报头压缩(ROHC,robust header compression)协议,针对ROHC协议中O模式下WLSB算法不够灵活的特点,提出一种自调整的窗基压缩编码算法(self-tuning Window based LSB,ST-WLSB),建立了三种信道状态,设置误码率界值,使用信道预估计技术计算出误码率,得出此时信道所处的状态,从而动态地改变滑动窗口大小.仿真测试表明,相比于WLSB算法,该算法具有更好的压缩效率.

LTE-A system is all IP network, with the continuous transmission of packets to the lower layer, the encapsulation of Internet protocols makes protocol header is Longer and longer, when the packet transmission part load is small, the header portion of the larger proportion,reduces bandwidth utilization in communication link. In order to improve the system throughput,LTE-A system use the robust header compression （ROHC） protocol on the OAI platform. For this characteristic that WLSB algorithm is not flexible in O mode of the ROHC protocol,it puts forward a kind of self-tuning robust header compression algorithm （ ST-WLSB ）, sets up three kinds of channel state and the error rate thresholds, uses the channel estimation technology to calculate error rate, so as to dynamically change the sliding window size with the channel state. The simulation tests show that the ST-WLSB algorithm has better compression efficiency compared to the WLSB algorithm.