An Improved Simplified-CE Stopping Criterion for BICM-ID System

2013 ◽  
Vol 846-847 ◽  
pp. 1262-1265
Author(s):  
Miao Miao Li ◽  
Jian Ping Li

Bit-interleaved coded modulation iterative decoding (BICM-ID) is an excellent bandwidth efficient transmission scheme,which owns remarkable bit-error-rate (BER) performance both in additive Gaussian noise (AWGN) channel and Rayleigh fading channel.But it leads to the increase of computational complexity and decoding delay at the receiver at the same time. In order to decrease the unnecessary iterations ,a variety of the stopping criteria are put forward . This paper presents an improved simplified cross-entropy (CE) stopping criterion based on Simplified-CE criterion, which calculates the value of CE just one time when Signal to Noise Ratio (SNR) is under 2dB to simplified the iterative process. Simulation results show that the improved Simplified-CE criterion can own the least iterative number when the SNR is under 2dB.And when the SNR is from 2.5dB to 4dB, it is about 12% less than CE criterion in the average iterative numbers.

2013 ◽  
Vol 433-435 ◽  
pp. 1530-1534
Author(s):  
Miao Miao Li ◽  
Jian Ping Li

The iterative process of bit-interleaved coded modulation iterative decoding (BICM-ID) leads to the increase of computational complexity and decoding delay at the receiver, although it owns remarkable bit-error-rate (BER) performance both in additive Gaussian noise (AWGN) channel and Rayleigh fading channel. A variety of the stopping criteria are put forward to reduce the unnecessary iterations in the process. This paper presents a simplified cross-entropy (CE) stopping criterion based on CE criterion, which sets self-adaptive thresholds for different SNRs to decide whether to calculate the CE in the receiver. Simulation results show that the simplified CE criterion can obtain a better performance and lower computational complexity. The iterative number of the simplified CE criterion is about 12.2% less than the conventional CE criterion.


Author(s):  
Roslina Mohamad ◽  
Mohamad Yusuf Mat Nasir ◽  
Nuzli Mohamad Anas

One of the most often-used stopping criteria is the cross-entropy stopping criterion (CESC). The CESC can stop turbo decoder iterations early by calculating mutual information improvements while maintaining bit error rate (BER) performance. Most research on iterative turbo decoding stopping criteria has utilised low-modulation methods, such as binary phase-shift keying. However, a high-speed network requires high modulation to transfer data at high speeds. Hence, a high modulation technique needs to be integrated into the CESC to match its speed. Therefore, the present paper investigated and analysed the effects of the CESC and quadrature amplitude modulation (QAM) on iterative turbo decoding. Three thresholds were simulated and tested under four situations: different code rates, different QAM formats, different code generators, and different frame sizes. The results revealed that in most situations, the use of CESC is suitable only when the signal-to-noise ratio (SNR) is high. This is because the CESC significantly reduces the average iteration number (AIN) while maintaining the BER. The CESC can terminate early at a high SNR and save more than 40% AIN compared with the fixed stopping criterion. Meanwhile, at a low SNR, the CESC fails to terminate early, which results in maximum AIN.


Author(s):  
Thắng

Bài viết đề xuất một xáo bộ trộn bít (gọi là New-block) sử dụng trong hệ thống BICM-ID (Bit-Interleaved Coded Modulation with Iterative Decoding) trên kênh pha đinh Rayleigh. Nó mang lại cho hệ thống giá trị hiệu suất BER (Tỷ lệ lỗi bit) xấp xỉ với bộ xáo trộn bít giả ngẫu nhiên ở vùng sàn lỗi, nhưng có phần cứng đơn giản hơn.


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