一种解决DTMB单载波正反频谱的搜索装置

Search Device for DTMB Single Carrier Frequency Spectrum

研究一种解决地面数字广播电视DTMB单载波正反频谱的搜索装置。计算对数似然比LLR的计算模块应用到时域解交织模块后,每解一帧低密度奇偶校验码LDPC时,可以将x和y进行交换,相当于正、反频谱切换。再计算LLR,根据LDPC解出的结果。可以确定当前信号的正、反频谱特性,而不需要重新复位整个解调器系统,这样可大大缩短搜索时间。它比通常做法可缩短约一半时间左右,减少了漏台概率。同时基于浮点二进制量化方法,可减少RAM存储。

In this paper,a search device for DTMB single carrier forward and backward spectrum of digital terrestrial multimedia broadcast is studied.After applying the LLR computing module to the time domain de-interleaving module,X and y can be exchanged for each frame of LDPC,which is equivalent to the forward and reverse spectrum switching.Then LLR is calculated and the result is obtained by LDPC.The forward and reverse spectrum characteristics of the current signal can be determined without resetting the whole demodulator system,which can greatly shorten the search time.It can shorten about half the time and reduce the probability of leakage.At the same time,based on floating-point binary quantization method,RAM storage can be reduced.