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从理论上给出一种Rice衰落条件下Reed-Solomon码级联空时分组码系统的差错性能分析方法,并推导给出级联码误比特率上界的数学表达式。理论分析和仿真结果表明,随着信噪比的增加,级联码系统的性能曲线迅速变好,获得了很高的编码增益。在误比特率为10-4时,与Reed-Solomon码的级联可以使衰落条件下空时分组码的性能提高大约5 dB。 相似文献
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In this paper, we present analytical bit error probability results for M-ary modulation concatenated with Reed Solomon (RS) codes. The analysis of bit error probability is nontrivial as the number of bits per symbol for the RS codes may not be an integer multiple of the number of bits per symbol for a modulation symbol. We propose a Markov chain technique which allows analytical evaluation of the bit error probability for such cases. The performance of RS coding with coherent biorthogonal, coherent/non-coherent orthogonal modulation over an additive white Gaussian noise (AWGN) channel is evaluated. Simulation of the bit error probability of RS code concatenated with a Nordstrom Robinson (NR) code as an inner code is performed and compared with the case of biorthogonal modulation. From the results, we notice that a stronger inner code gives better bit error probability. In addition, the throughput of the coded system with biorthogonal modulation over an AWGN channel is discussed. For a Rayleigh flat fading and block fading channel, we analyze the bit error probability of RS codes concatenated with biorthogonal modulation. From the result, we notice that a stronger outer code gives a better bit error probability for the case of Rayleigh flat fading channel. 相似文献
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基于Alamouti提出的BPSK调制下空时分组码在Rayleigh衰落信道中的码性能原理,推导出高阶(M ary)调制下Rician衰落信道中空时分组码的符号差错率的最小距离球界,并进行计算机仿真分析了两信道下引入空时分组码的多天线系统中发射和接收天线的分集增益,发射天线数量的“地板效应”以及Rician因子K对符号差错性能的影响。 相似文献
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K. Ujwal Deep Vidhyacharan Bhaskar 《International Journal of Communication Systems》2015,28(5):944-951
In this paper, space‐time block coding has been used in conjunction with Turbo codes to provide good diversity and coding gains. A new method of dividing turbo encoder and decoder into several parallel encoding and decoding blocks is considered. These blocks work simultaneously and yield a faster coding scheme in comparison to classical Turbo codes. The system concatenates fast Turbo coding as an outer code with Alamouti's G2 space‐time block coding scheme as an inner code, achieving benefits associated with both techniques including acceptable diversity and coding gain as well as short coding delay. In this paper, fast fading Rayleigh and Rician channels are considered for discussion. For Rayleigh fading channels, a fixed frame size and channel memory length of 5000 and 10, respectively, the coding gain is 7.5 dB and bit error rate (BER) of 10?4 is achieved at 7 dB. For the same frame size and channel memory length, Rician fading channel yields the same BER at about 4.5 dB. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Martin Johnston Rolando A. Carrasco 《International Journal of Communication Systems》2008,21(4):419-434
Hermitian codes are a class of very long algebraic‐geometric (AG) codes constructed from Hermitian curves, which outperform Reed–Solomon codes defined over the same finite fields and with the same code rates, as recently demonstrated by the authors. However, since there are no soft‐decision decoding algorithms for AG codes in the literature, the performance of Hermitian codes is limited and their potential is yet to be realized. An alternative method for achieving more significant coding gains is presented in this paper by serially concatenating long Hermitian codes with ring‐trellis‐coded modulation codes over the ring of integers ?4 and evaluating their performance through simulation results on the AWGN and Rayleigh fading channels. The scheme achieves large coding gains over single Hermitian and Reed–Solomon codes with no increase in bandwidth use and a performance comparable with the well‐known capacity‐approaching codes. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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根据不同中继节点建立的通信信道衰落特性的不同,利用中继节点可增强无线信道空间分集,提高整个链路的传输性能。纠错码的使用可更有效地提高信道传输效率的特点。文中介绍了基于LDPC码的多中继HARQ系统模型,在不降低传输速率的条件下,可更高效地传输数据。利用Matlab仿真了不同中继个数对系统平均误码率、吞吐量以及平均时延产生的不同影响,仿真结果表明,采用该系统模型可降低系统的平均误码率和平均时延,提高了系统的吞吐量。同时在码长较长的情况下,采用LDPC码的多中继HARQ系统性能优于采用Turbo码的多中继HARQ系统性能。 相似文献
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空时编码采用多发送天线设计信道编码,综合考虑分集、编码和调制,从而提高信号在无线衰落信道中的传输可靠性和数据传输率。介绍具有正交性的分组空时码的编译码方法。 相似文献
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I. K. Nissopoulos C. E. Dimakis S. S. Kouris 《International Journal of Communication Systems》2001,14(2):199-216
In this paper the performance of a concatenated coding scheme is evaluated over a slow Rayleigh fading HF ionospheric link with additive white Gaussian noise (AWGN). Well‐known Ungerboeck TCM techniques onto an 8‐PSK signal set are used as inner codes and Reed–Solomon block codes as outer codes. The coded/modulated signal is further differentially encoded before transmission to combat random phase changes. Block interleaving techniques are necessary to randomise long bursts of errors caused by the fading channel. The performance of the proposed concatenated coding system is investigated for various Doppler spreads. Significant coding gains are achieved over uncoded, diversity or other conventionally coded systems with a small bandwidth expansion. Finally the interesting effects of interleaving on the behaviour of the proposed systems are analysed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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The error rate performance, obtained on a Rayleigh fading channel, is determined and illustrated graphically for concatenated codes in which the outer code is a dual-k convolutional code and the inner code is either a Hadamard block code or a block orthogonal code. Comparison of the performance of these two types of concatenated codes is made on the basis of the same bandwidth utilization. It is also illustrated that the concatenated dual-k code yields a significant improvement in performance relative to the performance achieved with the inner code alone. 相似文献
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Tjhung T.T. Choon Tiong Ng Chun Sum Ng 《Vehicular Technology, IEEE Transactions on》1995,44(1):140-145
Reed Solomon codes with interleaving are used in a binary FM transmission affected by Rayleigh fading as encountered in land mobile radio. A new decoding algorithm is proposed which can be implemented in simple hardware. The error performance of the binary FM system with the RS code with one and two degrees of interleaving is measured. A significant reduction of error rate floor as a function of fading speed is noted and discussed 相似文献
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基于Alamouti提出的BPSK调制下空时分组码在Rayleigh衰落信道中的简单分集方案。推导出多发射和多接收天线系统中正交空时分组码在Nakagami衰落信道的BPSK调制下的比特差错率的最小距离球界,并推广到在高阶调制下衰落信道中系统符号差错率的性能。仿真分析和比较了空时分组码的多天线系统中发射和接收天线分集增益,以及信道相关参数的变化对系统误比特性能的影响。 相似文献
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The performance of sequential decoding of long constraint length convolutional codes is evaluated for Rayleigh fading channels. Sequential decoding is not practical below a certain theoretical signal-to-noise ratio, and these theoretical limits are calculated for a number of modulation methods and code rates. As an example, with BPSK modulation, soft decisions and code rate 1/2, the theoretical signal-to-noise ratio per information bit is 5.7 dB. Above this limit the bit error rate can be made arbitrarily small by increasing the constraint length at no significant complexity cost. Furthermore, it is shown that with carefully chosen quantization steps, 8 level uniform quantization gives a negligible loss also for sequential decoding on a Rayleigh fading channel. Simulation results using 8 level quantization correspond well with the theoretical performance bounds. Also, the performance on a correlated channel with finite interleaving has been obtained. With an interleaver depth of 50×50 and a normalized doppler frequency equal to 0.01 we are only 0.5 dB away from the performance with perfect interleaving. Finally, bit error rate results show this scheme to compete well with Turbo codes. 相似文献
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This paper investigates the performance of M-ary differential phase shift keying orthogonal frequency-division multiplexing (MDPSK-OFDM) systems employing peak power controlling block codes over frequency-selective Rayleigh fading channels. The block codes have a capability of both error correction and reduction of the peak-to-average power ratio (PAPR). To decode the block codes with reasonable complexity, the extended version of the ordered statistic decoding of Fossorier and Lin (see IEEE Trans. Inform. Theory, vol.41, p.1379-96, 1995) is utilized. The bit error rate performance of the block codes is evaluated over typical indoor radio channels by computer simulation and compared with that of the equivalent frequency diversity of the repetition codes. The significant coding gain and improvement of the irreducible error floor are observed under the constraint of the PAPR from 3 to 6 dB 相似文献
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The codeword error rate (WER) performance of noncoherent frequency-shift keying with soft decision decoding of block codes using Chase's second algorithm (1972) is investigated in a Rayleigh fading channel. The received signal envelope is sampled and used as channel measurement information. The theoretical upper and lower bounds of the WER are derived, assuming independent Rayleigh envelope samples in a received block. When the Golay (23, 12, 7) code is used, soft decision decoding with 6-bit error correction capability (3-bit error and 3-bit erasure) requires an average signal-to-noise power ratio about 5 dB lower than that for minimum distance decoding with 3-bit error correction to obtain a WER=10-3. The effects of bit interleaving on the WER performance when fading envelope variation is slow compared to the bit rate are investigated through computer simulations 相似文献
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该文提出了turbo码在最大比合并分集接收无线通信系统中纠错性能的联合上界。基于误差积分函数的简化计算式,推导了分集接收的多路信道分别具有不同衰落特性时,成对差错概率的精确表达式。以瑞利衰落信道为例,对采用turbo码的分集接收无线系统的性能进行了数值计算和仿真。结果表明:turbo码纠错性能联合上界数值计算式与仿真结果一致,可普遍用于信道衰落统计特性各不相同的分集接收系统。 相似文献