Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multipl...Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.展开更多
文章提出一种在片上系统(System on Chip,SoC)实现高吞吐率的有限状态熵编码(finite state entropy,FSE)算法。通过压缩率、速度、资源消耗、功耗4个方面对所提出的编码器和解码器与典型的硬件哈夫曼编码(Huffman coding,HC)进行性能比...文章提出一种在片上系统(System on Chip,SoC)实现高吞吐率的有限状态熵编码(finite state entropy,FSE)算法。通过压缩率、速度、资源消耗、功耗4个方面对所提出的编码器和解码器与典型的硬件哈夫曼编码(Huffman coding,HC)进行性能比较,结果表明,所提出的硬件FSE编码器和解码器具有显著优势。硬件FSE(hFSE)架构实现在SoC的处理系统和可编程逻辑块(programmable logic,PL)上,通过高级可扩展接口(Advanced eXtensible Interface 4,AXI4)总线连接SoC的处理系统和可编程逻辑块。算法测试显示,FSE算法在非均匀数据分布和大数据量情况下,具有更好的压缩率。该文设计的编码器和解码器已在可编程逻辑块上实现,其中包括1个可配置的缓冲模块,将比特流作为单字节或双字节配置输出到8 bit位宽4096深度或16 bit位宽2048深度的块随机访问存储器(block random access memory,BRAM)中。所提出的FSE硬件架构为实时压缩应用提供了高吞吐率、低功耗和低资源消耗的硬件实现。展开更多
In this paper, an asynchronous cooperative cellular system applied with space-time block coding (STBC) is investigated. A signal detector is proposed based on parallel interference cancellation (PIC), to cancel the in...In this paper, an asynchronous cooperative cellular system applied with space-time block coding (STBC) is investigated. A signal detector is proposed based on parallel interference cancellation (PIC), to cancel the inter-symbol interference (ISI) caused by the imperfect synchronization. Simulation results show that the proposed PIC detector can effiectively suppress the ISI, but there is still a comparatively high error floor, due to the co-channel interference (CCI) of the cellular system.展开更多
文摘Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.
文摘文章提出一种在片上系统(System on Chip,SoC)实现高吞吐率的有限状态熵编码(finite state entropy,FSE)算法。通过压缩率、速度、资源消耗、功耗4个方面对所提出的编码器和解码器与典型的硬件哈夫曼编码(Huffman coding,HC)进行性能比较,结果表明,所提出的硬件FSE编码器和解码器具有显著优势。硬件FSE(hFSE)架构实现在SoC的处理系统和可编程逻辑块(programmable logic,PL)上,通过高级可扩展接口(Advanced eXtensible Interface 4,AXI4)总线连接SoC的处理系统和可编程逻辑块。算法测试显示,FSE算法在非均匀数据分布和大数据量情况下,具有更好的压缩率。该文设计的编码器和解码器已在可编程逻辑块上实现,其中包括1个可配置的缓冲模块,将比特流作为单字节或双字节配置输出到8 bit位宽4096深度或16 bit位宽2048深度的块随机访问存储器(block random access memory,BRAM)中。所提出的FSE硬件架构为实时压缩应用提供了高吞吐率、低功耗和低资源消耗的硬件实现。
基金supported by the Shanghai Pujiang Program (Grant No.08PJ14057)the Science Foundation of Science and Technology Commission of Shanghai Municipality (Grant No.08220510900)
文摘In this paper, an asynchronous cooperative cellular system applied with space-time block coding (STBC) is investigated. A signal detector is proposed based on parallel interference cancellation (PIC), to cancel the inter-symbol interference (ISI) caused by the imperfect synchronization. Simulation results show that the proposed PIC detector can effiectively suppress the ISI, but there is still a comparatively high error floor, due to the co-channel interference (CCI) of the cellular system.
