In this letter, we consider a novel ultra-wideband (UWB) spatial multiplexing (SM) multiple input multiple output (MIMO) structure, which consists of prerake diversity combiners in the transmitter and a zero forcing (ZF) detector in the receiver. For a UWB SM MIMO system with N transmit antennas, M receive antennas, and L resolvable multipath components, it is shown that the proposed prerake combining-based MIMO detection scheme has the diversity order of (LN - M + 1) and its BER performance is analytically presented in a log-normal fading channel and also compared with that of a rake combining-based ZF scheme.

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This letter proposes Inverse QR two-dimensional Recursive Least Square (IQR-2D-RLS) adaptive channel estimation for Orthogonal Frequency Division Multiplexing (OFDM) systems (using Givens Rotations and Householder Transformations). It is more stable numerically than 2D-RLS algorithm. MATLAB simulations show that BER performance of IQR-2D-RLS algorithm is similar to that of 2D-RLS algorithm.

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We derive the average achievable rate of an adaptive wireless multicast method with antenna diversity in Nakagami fading channels when the rate is selected by the minimum signal-to-noise ratio (SNR) of the multicast group. Based on the limiting distribution of the minimum SNR, we then derive an approximation to the average achievable rate, which provides accurate values easily in a wide range of channel parameters.

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In a conventional downlink OFDMA system, an underlay secondary network is co-located to formulate a new implementation of OFDMA-based cognitive radio (OCR), where spectrum sharing is enabled between primary users and secondary users. With the introduced concept of accessible interference temperature, this new model can be easily implemented and may contribute to the future realization of OCR systems.

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This paper presents a fast and systematic architecture exploration method that realizes an efficient IEEE 802.11e based hardware/software co-design Medium Access Control (MAC) system architecture, which can achieve near theoretical MAC throughput for burst data transmission while complying with strict channel access time requirements. Our design approach uses SystemC based Transaction Level Modeling (TLM) framework to integrate reconfigurable general purpose computing and communication resources into the application model for rapid evaluation of core parameters, system performance, and application specific optimizations. As a result, a MAC system architecture that achieves a simulated MAC throughput of more than 100Mbps when transmitted at 260Mbps of Physical Layer (PHY) data rate is obtained. This result is verified with X-X-IMPLEMENTATION on a Xilinx Field-Programmable Gate Array (FPGA) board.

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A hot clutter mitigation algorithm based on Subbanding and Space Fast-time Adaptive Processing (Fast-time STAP) for Multi-channel Synthetic Aperture Radar (MSAR) is analyzed, and is compared with the method based on just fast-time STAP. Simulation results demonstrate that the method based on subbanding and fast-time STAP performs better than the method based on just fast-time STAP in hot clutter mitigation for MSAR.

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