渦輪乘積碼與時空區段聯結碼

Concatenation of Turbo Product Codes and Space Time Block Codes

李思賢(Ssu-Hsien Li)

指導教授 ： 馬尚智

中原大學/工學院/電機工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400104

摘要

摘要

無線通道由於受到多重路徑干擾的影響而有嚴重的通道衰減，使用時間或頻率的分集為有效減緩衰減的技術。Foschini與Gans及Telatar證明了多重輸入多重輸出系統除了可以經由空間分集來抵抗通道的衰減，同時也能增加系統的容量，這些研究引發了空時碼的研究，空時碼結合了通道編碼與多傳輸天線設計而能有效應用於多路徑干擾之無線通道。
Tarokh提出了時空籬柵碼(Space Time Trellis Codes)，在給定數目的天線條件下，能獲得最佳分集增益與一些編碼增益。另一方面由Berrou所提出的渦輪碼有非常強大的錯誤更正能力，將渦輪碼設計於多重傳輸天線是很不錯的編碼架構，如何能設計出具有最佳分集增益與優越除錯性能的時空渦輪碼仍是個開放的課題。
渦輪碼有兩個缺點，第一是於高訊雜比時，所發生的錯誤地板現象，第二是MAP解碼演算法具非常大的計算複雜度，Pyndiah將渦輪碼中反覆解碼的觀念，用於乘積碼(Product Code)中，稱之為渦輪乘積碼，渦輪乘積碼改進傳統渦輪碼的缺點，因此將渦輪乘積碼與多重傳輸天線結合，應能設計出性能良好，有效應用於無線通道的編碼系統。

關鍵字

渦輪碼 ； 多傳輸天線 ； 乘積碼 ； 時空區段碼

並列摘要

Abstract
The multipath wireless channel suffers severe attenuation. The Effective techniques to mitigate multipath fading are time and frequency diversity. Foschini,Gans and Telatar proved that multiple input multiple output can introduce spatial diversity and increased information capacity. These results have motivated a new area in error correcting codes . Space-Time Coding (STC) schemes can combine the channel code design and the use of multiple transmit antennas .

The Space Time Trellis Codes (STTC) proposed by Tarkoh combine the trellis coding with symbol mapping into multiple transmit antennas . The Coding scheme expansion is done in antenna space. The Turbo Codes proposed by Berrou have powerful error correcting abilities. It would be benefit to design turbo codes for multiple antenna systems. To design space-time turbo codes with maximum space diversity and outstanding performance is still an open question.

The Turbo Codes exhibited a troublesome error floor. Besides, the MAP algorithm which performs maximum likelihood bit estimation has a very large computation complexity . Recently turbo product codes (TPC) have been proposed . It can proved the performance of turbo codes. It is expected that TPC for multiple antenna systems would be powerful coding schemes with maximum diversity gain and large coding gain.

並列關鍵字

Multiple Transmit Antennas ； Turbo Codes ； Space Time Block Codes ； Product Codes

參考文獻

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