This paper presents a novel and cost effective method to be used in the optimization of the Gaussian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances th...This paper presents a novel and cost effective method to be used in the optimization of the Gaussian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances the performance of the noncoherent demodulation schemes by improving the Bit Error Rate (BER) and Frame Error Rate (FER) outcomes. Linear, Extended, and Unscented Kalman Filters are utilized in this technique. A simulation model, using Simulink, has been created to simulate the Bluetooth voice transmission system with the integrated filters. Results have shown improvements in the BER and FER, and that the Unscented Kalman Filters (UKF) have shown superior performance in comparison to the linear Kalman Filter (KF) and the Extended Kalman Filter (EKF). To the best of our knowledge, this research is the first to propose the usage of the UKF in the optimization of the Bluetooth System receivers in the presence of additive white Gaussian noise (AWGN), as well as interferences.展开更多
In orthogonal frequency-division multiplexing （OFDM） systems, the carrier frequency offset （CFO） destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have ...In orthogonal frequency-division multiplexing （OFDM） systems, the carrier frequency offset （CFO） destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have been developed to compensate for the CFO at the receiver. This paper describes a novel minimum output variance method for OFDM systems with CFO in additive white Gaussian noise channels. This method utilizes the phase and the amplitude of the received signal and reduces the mean square error of the CFO by about 3 dB compared with the original minimum output variance method.展开更多
Currently puncturing is the predominant strategy to construct high code rate turbo codes. The puncturing period and puncturing patterns, which have important effect on the performance of punctured turbo codes (PTC), y...Currently puncturing is the predominant strategy to construct high code rate turbo codes. The puncturing period and puncturing patterns, which have important effect on the performance of punctured turbo codes (PTC), yet have not received complete investigations, are addressed in this paper. Proposes on selecting puncturing period and puncturing patterns are presented. Since puncturing will alter the distance spectrum of turbo codes, the performance of PTC needs further consideration. We derive an analytical upper bound for PTC, based on the assumption of uniform puncturing defined in this paper. Finally, we present some numeric results on the performance of PTC.展开更多
Puncturing is the predominant strategy to construct high code rate turbo codes. Puncturing tables are crucial to the performance of punctured turbo codes(PTC). This paper developed a new searching algorithm of optimal...Puncturing is the predominant strategy to construct high code rate turbo codes. Puncturing tables are crucial to the performance of punctured turbo codes(PTC). This paper developed a new searching algorithm of optimal puncturing tables based on average distance spectrum(ADS) criterion. Consequently, some optimal puncturing tables were presented as the searching results. Finally, it presented the performance comparison among some optimal and bad puncturing tables by simulation.展开更多
An accurate frequency synchronization method using the zadoff-chu (ZC) constant envelop preamble is analyzed, and a new preamble weighted by pseudo-noise sequence is used for orthogonal frequency division multiplexing...An accurate frequency synchronization method using the zadoff-chu (ZC) constant envelop preamble is analyzed, and a new preamble weighted by pseudo-noise sequence is used for orthogonal frequency division multiplexing (OFDM) systems. Using this method, frequency offset estimator range is greatly enlarged with no loss in accuracy. The range of the frequency estimation is ±30 of subcarrier spacing using ZC sequence as preamble. Simulations in the MATLAB for an AWGN channel show that the proposed method achieves superior performance to existing techniques in terms of frequency accuracy and range.展开更多
时延是现代通信系统的一个重要指标。滑动窗译码能够在保证性能的基础上降低时延。基于滑动窗译码提出了一种不规则原模图低密度奇偶校验(low density parity check,LDPC)卷积码的构造方法。通过对基于AR4JA(accumulate-repeat-by-4-jag...时延是现代通信系统的一个重要指标。滑动窗译码能够在保证性能的基础上降低时延。基于滑动窗译码提出了一种不规则原模图低密度奇偶校验(low density parity check,LDPC)卷积码的构造方法。通过对基于AR4JA(accumulate-repeat-by-4-jagged-accumulate)的LDPC卷积码在AWGN(additive white Gaussian noise)信道下的P-EXIT性能分析发现,利用这种构造方式能够设计出多码率并且在BP译码和滑动窗译码方式下都能逼近容量限的LDPC卷积码。计算机仿真证明了基于AR4JA的LDPC卷积码性能优于规则的LDPC卷积码,而且在滑动窗译码方式下在降低至少56.7%时延的同时表现出了很好的性能。结合提出的不规则原模图LDPC卷积码的构造方法和滑动窗译码得到了一种能够实现译码时延与码字性能良好折中的码字构造有效方式。展开更多
文摘This paper presents a novel and cost effective method to be used in the optimization of the Gaussian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances the performance of the noncoherent demodulation schemes by improving the Bit Error Rate (BER) and Frame Error Rate (FER) outcomes. Linear, Extended, and Unscented Kalman Filters are utilized in this technique. A simulation model, using Simulink, has been created to simulate the Bluetooth voice transmission system with the integrated filters. Results have shown improvements in the BER and FER, and that the Unscented Kalman Filters (UKF) have shown superior performance in comparison to the linear Kalman Filter (KF) and the Extended Kalman Filter (EKF). To the best of our knowledge, this research is the first to propose the usage of the UKF in the optimization of the Bluetooth System receivers in the presence of additive white Gaussian noise (AWGN), as well as interferences.
基金Supported by the Major Program of the National Natural Science Foundation of China (No. 60496311) Basic Research Foundation of Tsinghua National Laboratory for Information Sci-ence and Technology (TNList)
文摘In orthogonal frequency-division multiplexing （OFDM） systems, the carrier frequency offset （CFO） destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have been developed to compensate for the CFO at the receiver. This paper describes a novel minimum output variance method for OFDM systems with CFO in additive white Gaussian noise channels. This method utilizes the phase and the amplitude of the received signal and reduces the mean square error of the CFO by about 3 dB compared with the original minimum output variance method.
基金This work is supported by National 863 Project of China (No. 2002 AA123046)
文摘Currently puncturing is the predominant strategy to construct high code rate turbo codes. The puncturing period and puncturing patterns, which have important effect on the performance of punctured turbo codes (PTC), yet have not received complete investigations, are addressed in this paper. Proposes on selecting puncturing period and puncturing patterns are presented. Since puncturing will alter the distance spectrum of turbo codes, the performance of PTC needs further consideration. We derive an analytical upper bound for PTC, based on the assumption of uniform puncturing defined in this paper. Finally, we present some numeric results on the performance of PTC.
文摘Puncturing is the predominant strategy to construct high code rate turbo codes. Puncturing tables are crucial to the performance of punctured turbo codes(PTC). This paper developed a new searching algorithm of optimal puncturing tables based on average distance spectrum(ADS) criterion. Consequently, some optimal puncturing tables were presented as the searching results. Finally, it presented the performance comparison among some optimal and bad puncturing tables by simulation.
文摘An accurate frequency synchronization method using the zadoff-chu (ZC) constant envelop preamble is analyzed, and a new preamble weighted by pseudo-noise sequence is used for orthogonal frequency division multiplexing (OFDM) systems. Using this method, frequency offset estimator range is greatly enlarged with no loss in accuracy. The range of the frequency estimation is ±30 of subcarrier spacing using ZC sequence as preamble. Simulations in the MATLAB for an AWGN channel show that the proposed method achieves superior performance to existing techniques in terms of frequency accuracy and range.
基金The National Natural Science Foundation of China(61271241)~~
文摘时延是现代通信系统的一个重要指标。滑动窗译码能够在保证性能的基础上降低时延。基于滑动窗译码提出了一种不规则原模图低密度奇偶校验(low density parity check,LDPC)卷积码的构造方法。通过对基于AR4JA(accumulate-repeat-by-4-jagged-accumulate)的LDPC卷积码在AWGN(additive white Gaussian noise)信道下的P-EXIT性能分析发现,利用这种构造方式能够设计出多码率并且在BP译码和滑动窗译码方式下都能逼近容量限的LDPC卷积码。计算机仿真证明了基于AR4JA的LDPC卷积码性能优于规则的LDPC卷积码,而且在滑动窗译码方式下在降低至少56.7%时延的同时表现出了很好的性能。结合提出的不规则原模图LDPC卷积码的构造方法和滑动窗译码得到了一种能够实现译码时延与码字性能良好折中的码字构造有效方式。
