Relay transmission technique can be utilized to increase coverage or enhance throughput for conventional cellular communication systems. There are two typical relaying schemes： amplify-and- forward （AF） and decode-...Relay transmission technique can be utilized to increase coverage or enhance throughput for conventional cellular communication systems. There are two typical relaying schemes： amplify-and- forward （AF） and decode-and-forward （DF）. This paper presents a new scheme named soft symbol Estimation and Forward （SEF） , which holds the advantages of both AF and DF, i.e. keeping soft information and obtaining decoding gain. This scheme has similar operations as DF except that the operations are performed in a soft-input-soft-output （SISO） fashion. The relay performs SISO deco- ding, SISO re-encoding and key point soft symbol estimation, which is derived based on the maxi- mum likelihood （ML） criteria. Simulation results prove that the proposed SEF scheme much outper- forms both AF and DF.展开更多
为了降低Turbo均衡中均衡器的复杂度,该文提出了符号方差反馈均衡算法(SVFE)。该算法是对精确的线性最小均方误差估计值(LMMSE)进行Taylor展开得到的。在该算法中,先利用时不变均衡器得到初步符号估计值,再根据先验符号方差对估计值加权...为了降低Turbo均衡中均衡器的复杂度,该文提出了符号方差反馈均衡算法(SVFE)。该算法是对精确的线性最小均方误差估计值(LMMSE)进行Taylor展开得到的。在该算法中,先利用时不变均衡器得到初步符号估计值,再根据先验符号方差对估计值加权,最后进行时不变滤波得到更佳的符号估计值。由于用到了时变的先验符号方差信息,其性能更接近精确的LMMSE均衡器。将所提算法用于Proakis C信道下的Turbo均衡处理,和时不变均衡算法进行仿真对比,所提算法将信噪比损失从0.83 d B降到了0.17 d B,并且仍可通过快速傅里叶变换降低为对数复杂度。展开更多
针对长期演进技术（LTE）下行多输入多输出正交频分多址链路（MIMO-OFDM）中的天线间干扰和多径干扰的问题,提出一种低复杂度的基于预编码矩阵的迭代均衡算法。该算法通过预编码矩阵将发射信号扩展到所有子载波上,降低由天线引起的部分...针对长期演进技术（LTE）下行多输入多输出正交频分多址链路（MIMO-OFDM）中的天线间干扰和多径干扰的问题,提出一种低复杂度的基于预编码矩阵的迭代均衡算法。该算法通过预编码矩阵将发射信号扩展到所有子载波上,降低由天线引起的部分子载波干扰。在接收端,利用最小均方误差排序QR分解（MMSE-SQRD）软输入软输出干扰消除均衡算法,从而避免传统基于MMSE并行软干扰消除均衡算法中矩阵求逆运算,进而降低了算法复杂度。在接收端,同时通过预编码对重建信号中误差进行扩展,进而缓解在迭代干扰消除过程中的误差传播。研究结果表明：在2发2收场景下,当误码率为10-3时,本文算法经过5次迭代后信噪比相比于传统MMSE-SQRD的迭代算法提高4.4~5.0 d B。展开更多
A reduced state Soft Input Soft Output (SISO) a posteriori probability algorithm for Seri-ally Concatenated Continuous Phase Modulation (SCCPM) is proposed in this paper. Based on the Reduced State Sequence Detection ...A reduced state Soft Input Soft Output (SISO) a posteriori probability algorithm for Seri-ally Concatenated Continuous Phase Modulation (SCCPM) is proposed in this paper. Based on the Reduced State Sequence Detection (RSSD),it has more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number,thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the perform-ance degradation is little with proper reduction scheme.展开更多
针对符号间干扰信道的多天线分集接收问题,提出一种单输入多输出(SIMO)系统盲迭代均衡算法。该算法利用吉布斯样本法处理思路,在SIMO条件下推导了信道冲击响应、发送符号等未知参数的条件后验分布,根据该条件概率逐个参数进行随机采样,...针对符号间干扰信道的多天线分集接收问题,提出一种单输入多输出(SIMO)系统盲迭代均衡算法。该算法利用吉布斯样本法处理思路,在SIMO条件下推导了信道冲击响应、发送符号等未知参数的条件后验分布,根据该条件概率逐个参数进行随机采样,通过不断迭代更新来逼近最大后验概率(MAP)估计的结果。该算法的一个显著特点是具有软输入软输出(SISO)结构,因此在编码系统中可以与信道译码结合,通过联合迭代进一步提升均衡的性能。计算机仿真结果表明,在严重符号间干扰信道条件下,SIMO系统盲迭代均衡算法的性能非常接近于已知信道时迭代均衡算法的性能,距离理想无符号间干扰信道分集合成的性能差距只有约1 d B。展开更多
An improved list sphere decoder （ILSD） is proposed based on the conventional list sphere decoder （LSD） and the reduced- complexity maximum likelihood sphere-decoding algorithm. Unlike the conventional LSD with fix...An improved list sphere decoder （ILSD） is proposed based on the conventional list sphere decoder （LSD） and the reduced- complexity maximum likelihood sphere-decoding algorithm. Unlike the conventional LSD with fixed initial radius, the ILSD adopts an adaptive radius to accelerate the list cdnstruction. Characterized by low-complexity and radius-insensitivity, the proposed algorithm makes iterative joint detection and decoding more realizable in multiple-antenna systems. Simulation results show that computational savings of ILSD over LSD are more apparent with more transmit antennas or larger constellations, and with no performance degradation. Because the complexity of the ILSD algorithm almost keeps invariant with the increasing of initial radius, the BER performance can be improved by selecting a sufficiently large radius.展开更多
In this paper, serially concatenated continuous phase modulation （SCCPM） system is analyzed and a reduced state soft input soft output （SlSO） a posteriori probability algorithm is proposed. Based on the reduced st...In this paper, serially concatenated continuous phase modulation （SCCPM） system is analyzed and a reduced state soft input soft output （SlSO） a posteriori probability algorithm is proposed. Based on the reduced state sequence detection （RSSD）, it has the more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number, thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the performance degradation is little with proper reduction scheme.展开更多
文摘Relay transmission technique can be utilized to increase coverage or enhance throughput for conventional cellular communication systems. There are two typical relaying schemes： amplify-and- forward （AF） and decode-and-forward （DF）. This paper presents a new scheme named soft symbol Estimation and Forward （SEF） , which holds the advantages of both AF and DF, i.e. keeping soft information and obtaining decoding gain. This scheme has similar operations as DF except that the operations are performed in a soft-input-soft-output （SISO） fashion. The relay performs SISO deco- ding, SISO re-encoding and key point soft symbol estimation, which is derived based on the maxi- mum likelihood （ML） criteria. Simulation results prove that the proposed SEF scheme much outper- forms both AF and DF.
文摘为了降低Turbo均衡中均衡器的复杂度,该文提出了符号方差反馈均衡算法(SVFE)。该算法是对精确的线性最小均方误差估计值(LMMSE)进行Taylor展开得到的。在该算法中,先利用时不变均衡器得到初步符号估计值,再根据先验符号方差对估计值加权,最后进行时不变滤波得到更佳的符号估计值。由于用到了时变的先验符号方差信息,其性能更接近精确的LMMSE均衡器。将所提算法用于Proakis C信道下的Turbo均衡处理,和时不变均衡算法进行仿真对比,所提算法将信噪比损失从0.83 d B降到了0.17 d B,并且仍可通过快速傅里叶变换降低为对数复杂度。
文摘针对长期演进技术（LTE）下行多输入多输出正交频分多址链路（MIMO-OFDM）中的天线间干扰和多径干扰的问题,提出一种低复杂度的基于预编码矩阵的迭代均衡算法。该算法通过预编码矩阵将发射信号扩展到所有子载波上,降低由天线引起的部分子载波干扰。在接收端,利用最小均方误差排序QR分解（MMSE-SQRD）软输入软输出干扰消除均衡算法,从而避免传统基于MMSE并行软干扰消除均衡算法中矩阵求逆运算,进而降低了算法复杂度。在接收端,同时通过预编码对重建信号中误差进行扩展,进而缓解在迭代干扰消除过程中的误差传播。研究结果表明：在2发2收场景下,当误码率为10-3时,本文算法经过5次迭代后信噪比相比于传统MMSE-SQRD的迭代算法提高4.4~5.0 d B。
基金Supported by NSFC & Microsoft Asia (60372048)China TRAPOYT, NSFC key project (60496316)+2 种基金863 Project (2005AA123910)RFDP (20050701007)MOE Key Project (104171).
文摘A reduced state Soft Input Soft Output (SISO) a posteriori probability algorithm for Seri-ally Concatenated Continuous Phase Modulation (SCCPM) is proposed in this paper. Based on the Reduced State Sequence Detection (RSSD),it has more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number,thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the perform-ance degradation is little with proper reduction scheme.
文摘针对符号间干扰信道的多天线分集接收问题,提出一种单输入多输出(SIMO)系统盲迭代均衡算法。该算法利用吉布斯样本法处理思路,在SIMO条件下推导了信道冲击响应、发送符号等未知参数的条件后验分布,根据该条件概率逐个参数进行随机采样,通过不断迭代更新来逼近最大后验概率(MAP)估计的结果。该算法的一个显著特点是具有软输入软输出(SISO)结构,因此在编码系统中可以与信道译码结合,通过联合迭代进一步提升均衡的性能。计算机仿真结果表明,在严重符号间干扰信道条件下,SIMO系统盲迭代均衡算法的性能非常接近于已知信道时迭代均衡算法的性能,距离理想无符号间干扰信道分集合成的性能差距只有约1 d B。
基金The National Natural Science Founda-tion of China ( No 60496316)the National Hi-Tech Re-search and Development Program (863) of China (No2006-AA01Z270)
文摘An improved list sphere decoder （ILSD） is proposed based on the conventional list sphere decoder （LSD） and the reduced- complexity maximum likelihood sphere-decoding algorithm. Unlike the conventional LSD with fixed initial radius, the ILSD adopts an adaptive radius to accelerate the list cdnstruction. Characterized by low-complexity and radius-insensitivity, the proposed algorithm makes iterative joint detection and decoding more realizable in multiple-antenna systems. Simulation results show that computational savings of ILSD over LSD are more apparent with more transmit antennas or larger constellations, and with no performance degradation. Because the complexity of the ILSD algorithm almost keeps invariant with the increasing of initial radius, the BER performance can be improved by selecting a sufficiently large radius.
基金the National Natural Science Foundation of China (Grant Nos. 60496316, 60532060 and 60572146)the Research Fund for the Doctoral Program of Higher Education (Grant No. 20050701007)China Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE, MOE Key Project (Grant No. 107103)
文摘In this paper, serially concatenated continuous phase modulation （SCCPM） system is analyzed and a reduced state soft input soft output （SlSO） a posteriori probability algorithm is proposed. Based on the reduced state sequence detection （RSSD）, it has the more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number, thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the performance degradation is little with proper reduction scheme.
