2,299 research outputs found
Hybrid beamforming for single carrier mmWave MIMO systems
Hybrid analog and digital beamforming (HBF) has been recognized as an
attractive technique offering a tradeoff between hardware implementation
limitation and system performance for future broadband millimeter wave (mmWave)
communications. In contrast to most current works focusing on the HBF design
for orthogonal frequency division multiplexing based mmWave systems, this paper
investigates the HBF design for single carrier (SC) systems due to the
advantage of low peak-to-average power ratio in transmissions. By applying the
alternating minimization method, we propose an efficient HBF scheme based on
the minimum mean square error criterion. Simulation results show that the
proposed scheme outperforms the conventional HBF scheme for SC systems.Comment: IEEE GlobalSIP2018, Feb. 201
UTHM water quality classification based on sub index
River or stream at their source is unpolluted, but as water flow downstream, the river or lake is receiving point and non-point pollutant source. Ammoniacal nitrogen (NH3- N) and suspended solids (SS) strongly influences the dynamics of the dissolved oxygen in the water. Studies on monitoring this parameter were conducted for a river or lake but limited to the small man-made lake. This study is initiate to determine the changes in water quality of UTHM watershed as the water flows from upstream to downstream. The monitoring of NH3-N and TSS were monitored at two sampling schemes, 1) at the two-week interval and, 2) at a daily basis followed by the determination of the water quality sub-index particularly SIAN and SISS. The results showed that the two lakes in UTHM watershed were classified as polluted. In conclusion, the remedial action should be implemented to improve the water quality to meet the requirements at least to meet the recreational purpose
Blind adaptive equalizer for broadband MIMO time reversal STBC based on PDF fitting
In this paper, we propose a new blind adaptive technique used for the equalisation of space-time block coded (STBC) signals transmitted over a dispersive MIMO channel. The proposed approach is based on minimising the difference between the probability density function (PDF) of the equalizer output — estimated via the Parzen window method — and a desired PDF based on the source symbols. The cost function combines this PDF fitting with an orthogonality criterion derived from the STBC structure of the transmitted data in order to discourage the extraction of identical signals. This cost function motivates an effective and low-cost stochastic gradient descent algorithm for adapting the equaliser. The performance is demonstrated in a number of simulations and benchmarked against other blind schemes for the equalisation of STBC over broadband MIMO channels
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