无线电通信技术
無線電通信技術
무선전통신기술
RADIO COMMUNICATIONS TECHNOLOGY
2012年
1期
29-31
,共3页
周继宇%张雅奇%徐伯庆
週繼宇%張雅奇%徐伯慶
주계우%장아기%서백경
Turbo译码%Log—MAP算法%校正函数%非均匀量化%软迭代译码
Turbo譯碼%Log—MAP算法%校正函數%非均勻量化%軟迭代譯碼
Turbo역마%Log—MAP산법%교정함수%비균균양화%연질대역마
Turbo encode%Log-MAP algorithm%correction function%non-uniform quantization%soft iterative decode
为了简化Log—MAP算法、减小其硬件查表实现时所占用的外存储单元，采用了非均匀量化的方法分别对Log—MAP算法中的校正函数进行两电平和五电平近似，从而得到相应的量化函数。并将该量化函数用于LTETurbo译码器，在AWGN信道上进行软迭代译码仿真。仿真结果表明，两电平和五电平非均匀量化的近似Log—MAP算法将Max—Log—MAP算法的译码性能提高了0．2～0．3dB，与原Log—MAP算法性能接近，但却能大大减少查表时需要检索的数据量。
為瞭簡化Log—MAP算法、減小其硬件查錶實現時所佔用的外存儲單元，採用瞭非均勻量化的方法分彆對Log—MAP算法中的校正函數進行兩電平和五電平近似，從而得到相應的量化函數。併將該量化函數用于LTETurbo譯碼器，在AWGN信道上進行軟迭代譯碼倣真。倣真結果錶明，兩電平和五電平非均勻量化的近似Log—MAP算法將Max—Log—MAP算法的譯碼性能提高瞭0．2～0．3dB，與原Log—MAP算法性能接近，但卻能大大減少查錶時需要檢索的數據量。
위료간화Log—MAP산법、감소기경건사표실현시소점용적외존저단원，채용료비균균양화적방법분별대Log—MAP산법중적교정함수진행량전평화오전평근사，종이득도상응적양화함수。병장해양화함수용우LTETurbo역마기，재AWGN신도상진행연질대역마방진。방진결과표명，량전평화오전평비균균양화적근사Log—MAP산법장Max—Log—MAP산법적역마성능제고료0．2～0．3dB，여원Log—MAP산법성능접근，단각능대대감소사표시수요검색적수거량。
This paper adopts two-level and five-level non-uniform quantization to approximate the correction function of Log-MAP so as to simplify Log-MAP algorithm and diminish the storage of hardware implementation. Then, both of them are used in turbo decoder of LTE system and simulated on AWGN channel. The simulation results show that error-correcting capability of non-uniform quantizing approximation Log-MAP algorithm is higher 0.2 -0. 3 dB at least than Max-log-MAP algorithm and near to Log-MAP algorithm, while it has better performance in hardware implementation compared with Log-MAP algorithm.
