适用于体全息存储系统的调制-阵列码的研究

Study on Modulation-array Code Suitable for Digital Holographic Storage

提出了一种适用于体全息存储系统读写数据处理的新的编码结构 :调制 阵列码 ,同时提出了与其相适应的软判决度量方法。在此基础之上综合调制码探测、软判决、阵列码纠错和Turbo码译码原理 ,形成了一种新的迭代译码算法。实验结果表明 ,在信道的信噪比较低且有起伏 ,信道噪声参数不易统计的情况下 ,它能充分利用输入信号所包含的信息 ,只要原始误码率 (定义为采用全局最佳阈值量化后的误码率 )低于 4× 1 0 -2 ,8× 1 0调制 阵列码的使用效果就可与 1∶2调制码 (二者码率相当 )的使用效果相当 ;当原始误码率低于 1× 1 0 -2 后 ,其使用效果显著优于 1∶2调制码。将这种新的编译码技术用于包含音频和视频的多媒体数据的全息存储 。

A modified coding structure, Modulation Array (MA) code, and a novel soft decision method corresponding to MA code are proposed for data processing in digital holographic storage systems. Also developed based on the MA code is a new iterative decoding algorithm, which integrates principles of modulation code detection, soft decision, array code error correction and Turbo code decoding. Experimental results show that when the signal to noise ratio in the channel is low and varying, and the noise parameters are difficult to calculate, this MA code can exploit the information contained in the input data effectively. As long as the raw bit error rate (BER), which is defined as the BER after global optimum threshold quantization, is around 4×10 -2 the output BER of the 8×10 MA code is equivalent to that of traditional 1∶2 modulation code (both codes have the similar code rate). For the raw BER lower than 1×10 -2 the MA code exhibits obvious advantage over the 1∶2 modulation code. Using these techniques, a preliminary experiment has been conducted to store and successfully replay multimedia data including video and audio information.