OFDM中的自适应Turbo编码调制  

Adaptive Turbo coded modulation for OFDM

作　　者：佘小明 周世东[1] 许希斌[1] 姚彦[1] 

机构地区：[1]清华大学电子工程系微波与数字通信技术国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2004年第4期507-510,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家"八六三"高技术项目(2001AA123012)

摘　　要：自适应编码调制(AMC)技术可以有效地提高无线数据传输的频谱利用率。为在目标误码率RBE(BER)限制下优化系统吞吐提出了一种基于正交频分复用(OFDM)的恒功率、变速率的自适应Turbo编码调制的方法,以及基于容量估计的自适应算法。仿真表明,在目标BER为10-4下,此自适应OFDM方法与相同吞吐下的固定Turbo编码调制相比,有7.5dB以上的信噪比(SNR)增益。同时,与基于固定门限的自适应调制算法不同,基于容量估计的自适应算法下,子带数目的减少不会带来吞吐性能的恶化,可以用来进一步降低系统的反馈开销。Adaptive modulation and coding (AMC) can effectively improve the spectral efficiency for wireless data transmissions. A fixed-power variable-rate Turbo coded modulation scheme was developed with an adaptation algorithm based on capacity evaluation for orthogonal frequency division multiplexing (OFDM). The objective is to improve the overall throughput given a target bit-error-rate (BER). Simulation results showed that the adaptive OFDM scheme exhibited more than 7.5 dB SNR gain for a target BER of 10^-4 relative to non-adaptive Turbo coded modulation for the same throughput. Moreover, unlike fixed threshold adaptive modulation, the throughput did not degrade with this capacity evaluation algorithm when the number of subbands and the feedback overhead were reduced.

关 键 词：OFDM 自适应编码调制 TURBO编码调制 移动通信 正交频分复用 数据传输 

分 类 号：TN911.22[电子电信—通信与信息系统]