在全双工多中继协作无线携能通信网络中,传统的中继选择算法未考虑到未被选择中继的闲置利用问题,导致中继数量增加时网络的性能浪费愈加严重,如何开发未被选择中继的剩余潜能成为提升网络性能的关键。对此,设计了一种新的HTT(Harvest t...在全双工多中继协作无线携能通信网络中,传统的中继选择算法未考虑到未被选择中继的闲置利用问题,导致中继数量增加时网络的性能浪费愈加严重,如何开发未被选择中继的剩余潜能成为提升网络性能的关键。对此,设计了一种新的HTT(Harvest then Transmit)功率消耗方案,在中继配备电池的情形下,通过充分利用中继处的能量收集模块增加了被选择中继处的发射功率,从而进一步提升了系统容量。此外,针对提出的新的HTT功率消耗方案,考虑了BIKT(Battery Information Known at Transmitter)和BIUT(Battery Information Unknown at Transmitter)两种应用场景。仿真实验的结果表明,3种中继选择算法,即单中继选择算法、贪婪中继选择算法和穷竭搜索算法,在采用提出的新的HTT功率消耗方案后,无论是应用于BIKT场景还是BIUT场景均能有效提升系统容量并降低中断概率。展开更多
Estimation and detection algorithms for orthogonal frequency division multiplexing (OFDM) systems can be de-veloped based on the sum-product algorithms, which operate by message passing in factor graphs. In this paper...Estimation and detection algorithms for orthogonal frequency division multiplexing (OFDM) systems can be de-veloped based on the sum-product algorithms, which operate by message passing in factor graphs. In this paper, we apply the sampling method (Monte Carlo) to factor graphs, and then the integrals in the sum-product algorithm can be approximated by sums, which results in complexity reduction. The blind receiver for OFDM systems can be derived via Sequential Monte Carlo (SMC) in factor graphs, the previous SMC blind receiver can be regarded as the special case of the sum-product algorithms using sampling methods. The previous SMC blind receiver for OFDM systems needs generating samples of the channel vector assuming the channel has an a priori Gaussian distribution. In the newly-built blind receiver, we generate samples of the virtual-pilots instead of the channel vector, with channel vector which can be easily computed based on virtual-pilots. As the size of the vir-tual-pilots space is much smaller than the channel vector space, only small number of samples are necessary, with the blind de-tection being much simpler. Furthermore, only one pilot tone is needed to resolve phase ambiguity and differential encoding is not used anymore. Finally, the results of computer simulations demonstrate that the proposal can perform well while providing sig-nificant complexity reduction.展开更多
It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispens...It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispensable to meet the demands for high throughput and low latency in next generation mobile communication systems. This paper unveils the fact that interleavers based on permutation polynomials modulo N are contention-free for every window size W, a factor of the intedeaver length N, which, also called maximum contention-free interleavers.展开更多
文摘在全双工多中继协作无线携能通信网络中,传统的中继选择算法未考虑到未被选择中继的闲置利用问题,导致中继数量增加时网络的性能浪费愈加严重,如何开发未被选择中继的剩余潜能成为提升网络性能的关键。对此,设计了一种新的HTT(Harvest then Transmit)功率消耗方案,在中继配备电池的情形下,通过充分利用中继处的能量收集模块增加了被选择中继处的发射功率,从而进一步提升了系统容量。此外,针对提出的新的HTT功率消耗方案,考虑了BIKT(Battery Information Known at Transmitter)和BIUT(Battery Information Unknown at Transmitter)两种应用场景。仿真实验的结果表明,3种中继选择算法,即单中继选择算法、贪婪中继选择算法和穷竭搜索算法,在采用提出的新的HTT功率消耗方案后,无论是应用于BIKT场景还是BIUT场景均能有效提升系统容量并降低中断概率。
基金Project supported by the National Hi-Tech Research and Develop-ment Program (863) of China (No. 2003AA123310) and the National Natural Science Foundation of China (No. 60332030)
文摘Estimation and detection algorithms for orthogonal frequency division multiplexing (OFDM) systems can be de-veloped based on the sum-product algorithms, which operate by message passing in factor graphs. In this paper, we apply the sampling method (Monte Carlo) to factor graphs, and then the integrals in the sum-product algorithm can be approximated by sums, which results in complexity reduction. The blind receiver for OFDM systems can be derived via Sequential Monte Carlo (SMC) in factor graphs, the previous SMC blind receiver can be regarded as the special case of the sum-product algorithms using sampling methods. The previous SMC blind receiver for OFDM systems needs generating samples of the channel vector assuming the channel has an a priori Gaussian distribution. In the newly-built blind receiver, we generate samples of the virtual-pilots instead of the channel vector, with channel vector which can be easily computed based on virtual-pilots. As the size of the vir-tual-pilots space is much smaller than the channel vector space, only small number of samples are necessary, with the blind de-tection being much simpler. Furthermore, only one pilot tone is needed to resolve phase ambiguity and differential encoding is not used anymore. Finally, the results of computer simulations demonstrate that the proposal can perform well while providing sig-nificant complexity reduction.
基金Project (No. 60332030) supported by the National Natural ScienceFoundation of China
文摘It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispensable to meet the demands for high throughput and low latency in next generation mobile communication systems. This paper unveils the fact that interleavers based on permutation polynomials modulo N are contention-free for every window size W, a factor of the intedeaver length N, which, also called maximum contention-free interleavers.
