A multi dimensional concatenation scheme for block codes is introduced, in which information symbols are interleaved and re encoded for more than once. It provides a convenient platform to design high performance co...A multi dimensional concatenation scheme for block codes is introduced, in which information symbols are interleaved and re encoded for more than once. It provides a convenient platform to design high performance codes with flexible interleaver size. Coset based MAP soft in/soft out decoding algorithms are presented for the F24 code. Simulation results show that the proposed coding scheme can achieve high coding gain with flexible interleaver length and very low decoding complexity.展开更多
In this paper we propose two iterative algorithms of joint channel estimation and symbol detection for Orthogonal Frequency Division Multiplexing (OFDM) systems. In which, superimposed pilot scheme is adopted and an i...In this paper we propose two iterative algorithms of joint channel estimation and symbol detection for Orthogonal Frequency Division Multiplexing (OFDM) systems. In which, superimposed pilot scheme is adopted and an initial Channel State Information (CSI) is obtained by employing a first-order statistic. In each subsequent iteration, we propose two algorithms to update the CSI. The Mean Square Error (MSE) of channel estimation and Bit Error Rate (BER) performance are given and simulation results demonstrate that the iterative algorithm using method B has good perform-ance approaching the ideal condition.展开更多
As a necessary input parameter for maximum a-posteriori(MAP)decoding algorithm,SNR is normally obtained from the channel estimation unit.Corresponding research indicated that SNR estimation deviation degraded the perf...As a necessary input parameter for maximum a-posteriori(MAP)decoding algorithm,SNR is normally obtained from the channel estimation unit.Corresponding research indicated that SNR estimation deviation degraded the performance of Turbo decoding significantly.In this paper,MAP decoding algorithm with SNR estimation de-viation was investigated in detail,and the degradation mechanism of Turbo decoding was explained analytically.The theoretical analysis and computer simulation disclosed the specific reasons for the performance degradation when SNR estimation was less than the actual value,and for the higher sensitivity of SNR estimation to long-frame Turbo codes.展开更多
文摘A multi dimensional concatenation scheme for block codes is introduced, in which information symbols are interleaved and re encoded for more than once. It provides a convenient platform to design high performance codes with flexible interleaver size. Coset based MAP soft in/soft out decoding algorithms are presented for the F24 code. Simulation results show that the proposed coding scheme can achieve high coding gain with flexible interleaver length and very low decoding complexity.
基金Supported by National "863" Project (No.2002AA123031).
文摘In this paper we propose two iterative algorithms of joint channel estimation and symbol detection for Orthogonal Frequency Division Multiplexing (OFDM) systems. In which, superimposed pilot scheme is adopted and an initial Channel State Information (CSI) is obtained by employing a first-order statistic. In each subsequent iteration, we propose two algorithms to update the CSI. The Mean Square Error (MSE) of channel estimation and Bit Error Rate (BER) performance are given and simulation results demonstrate that the iterative algorithm using method B has good perform-ance approaching the ideal condition.
基金supported by the National Natural Science Foundation of China(No.60272070).
文摘As a necessary input parameter for maximum a-posteriori(MAP)decoding algorithm,SNR is normally obtained from the channel estimation unit.Corresponding research indicated that SNR estimation deviation degraded the performance of Turbo decoding significantly.In this paper,MAP decoding algorithm with SNR estimation de-viation was investigated in detail,and the degradation mechanism of Turbo decoding was explained analytically.The theoretical analysis and computer simulation disclosed the specific reasons for the performance degradation when SNR estimation was less than the actual value,and for the higher sensitivity of SNR estimation to long-frame Turbo codes.
