A CORDIC based QR Decomposition Technique for MIMO Detection

CORDIC based improved real and complex QR Decomposition (QRD) for channel pre-processing operations in (Multiple-Input Multiple-Output) MIMO detectors are presented in this paper. The proposed design utilizes pipelining and parallel processing techniques and reduces the latency and hardware complexity of the module respectively. Computational complexity analysis report shows the superiority of our module by 16% compared to literature. The implementation results reveal that the proposed QRD takes shorter latency compared to literature. The power consumption of 2x2 real channel matrix and 2x2 complex channel matrix was found to be 12mW and 44mW respectively on the state-of-the-art Xilinx Virtex 5 FPGA

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

MODIFIED K-BEST DETECTION ALGORITHM FOR MIMO SYSTEMS

ABSTRACT This paper presents a VLSI implementation of reduced hardware-complexity and reconfigurable signal detector for MIMO (Multiple-Input Multiple-Output) systems. In recent wireless communication system, MIMO technique is being adopted to meet the rapidly increasing demands for the multimedia services and to achieve better QoS(Quality of Service). Maximum likelihood (ML) detection is the optimal hard decision detection for MIMO systems. FPGA implementation of ML detector becomes infeasible as its complexity grows exponentially with the number of antennas. Therefore, we propose a modified K-best detector algorithm which employs parallel and distributed sorting strategy that has a constant throughput and near-ML detection solution. The proposed MIMO detector was implemented targeting Xilinx Virtex 6 device for a 2x2, 4 QAM system and it achieves throughput of 12.23Mbps. The resource utilization results are listed and compared with the existing algorithm. The total on-chip power estimated is 1.57W. Keywords: MIMO (multiple-input multiple-output), maximum-likelihood (ML), sphere decoder, K-best algorithm, very large scale integration (VLSI)