用Duffing振子阵列解调微弱π/4-DQPSK信号  

Using the Duffing oscillator arrays to demodulate the weakπ/4-DQPSK signal

作　　者：魏世朋[1] 张天骐[1] 白娟[1] 余熙[1] 

机构地区：[1]重庆邮电大学信号与信息处理重庆市重点实验室,重庆400065

出　　处：《电子技术应用》2011年第11期120-124,共5页Application of Electronic Technique

基　　金：国家自然科学基金项目(61071196);国家自然科学基金-中物院NSAF联合基金项目(10776040);教育部新世纪优秀人才支持计划(NCET-10-0927)

摘　　要：首次提出了微弱π/4-DQPSK信号Dumng振子阵列的解调算法,并用计算机对此算法进行了相应的仿真验证,同时还创造性地提出了星座图重叠划分,功率谱熵计算阵列和Dumng振子码元分界点搜寻器。先将π/4-DQPSK星座图的8个点划分成相重叠的四个区域,然后用功率谱熵来判定不同区域内Dumng振子的不同响应,最后依据当前时刻Duffing振子阵列的不同响应来断定所传送的数字信息。计算机仿真结果表明,本算法切实可行,在高斯信道中解调信噪比最低可达-15.6 dB。Concerning the high BER and the phase ambiguity of the π/4-DQPSK signal＇s traditional demodulation method in low SNR, the demodulation method based on duffing oscillator arrays was studied. π/4-DQPSK signal＇s 8 phases correspond with the 8 points in its constellation figure, firstly, the constellation is divided into 4 overlapping regions and each region contains 3 phases, then we put the π/4-DQPSK into the Duffing oscillator arrays as the tested signal, we can know which regions the current π/4-DQPSK is in from he power spectrum entropy of Duffing oscillator arrays＇s output signal. Later, use a set of decision rules to decide which point the current signal belong and recovered the I, Q branch signals. Finally, use the differential decoding and parallel /serial conversion to recover the digital information which we sent out. The simulation results show that this demodulation method is suitable for demodulating the π/4-DQPSK signal in Gaussian channel and Rice channel.

关 键 词：Duffing振子阵列 Π/4-DQPSK 功率谱熵 星座图划分 组合判决赋值 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]