A study on the zero-forcing beamforming(ZFBF)scheme with antenna selection at user terminals in downlink multi-antenna multi-user systems is presented.Simulation results show that the proposed ZFBF scheme with receive...A study on the zero-forcing beamforming(ZFBF)scheme with antenna selection at user terminals in downlink multi-antenna multi-user systems is presented.Simulation results show that the proposed ZFBF scheme with receiver antenna selection(ZFBF-AS)achieves considerable throughput improvement over the ZFBF scheme with single receiver antenna.The results also show that,with multi-user diversity,the ZFBF-AS scheme approaches the throughput performance of the ZFBF scheme using all receiver antennas(ZFBF-WO-AS)when the base station adopts semi-orthogonal user selection(SUS)algorithm,and achieves larger throughput when the base station adopts the Round-robin scheduling algorithm.Compared with ZFBF-WO-AS,the proposed ZFBF-AS scheme can reduce the cost of user equipments and the channel state information requirement at the transmitter(CSIT)as well as the multiuser scheduling complexity at the transmitter.展开更多
研究了(/%)0.023Al_(sol)、0.035Al_(sol)、0.018～0.019Al_(sol)-0.012～0.014Ti和0.019～0.020Al_(sol)-0.031～0.032Nb微合金化对60 t BOF-LF-VD-300 mm×360 mm CC-连轧工艺生产的Φ120 mm ZF7渗碳钢(/%:0.18～0.20C、0.22～0.2...研究了(/%)0.023Al_(sol)、0.035Al_(sol)、0.018～0.019Al_(sol)-0.012～0.014Ti和0.019～0.020Al_(sol)-0.031～0.032Nb微合金化对60 t BOF-LF-VD-300 mm×360 mm CC-连轧工艺生产的Φ120 mm ZF7渗碳钢(/%:0.18～0.20C、0.22～0.25Si、1.22～1.30Mn、0.008～0.016P、0.019～0.029S、1.19～1.25Cr、0.001 8～0.002 2B)930℃加热时晶粒度混晶的影响。结果表明,在930℃7.5 h热处理条件下,当Al_(sol)为0.035%时ZF7钢未发生混晶现象,当钢中(/%)0.023Al_(sol)或0.018～0.019Al_(sol)-0.012～0.014Ti或0.019～0.020Al_(sol)-0.031～0.032Nb微合金化时,ZF7钢均发生了混晶现象,说明钢中有足够的Al_(sol)含量是防止ZF7钢发生混晶的关键因素。展开更多
基金supported by the National Natural Science Foundation of China(60496314)the National High Technology Research and Development Program of China(2006AA01Z266).
文摘A study on the zero-forcing beamforming(ZFBF)scheme with antenna selection at user terminals in downlink multi-antenna multi-user systems is presented.Simulation results show that the proposed ZFBF scheme with receiver antenna selection(ZFBF-AS)achieves considerable throughput improvement over the ZFBF scheme with single receiver antenna.The results also show that,with multi-user diversity,the ZFBF-AS scheme approaches the throughput performance of the ZFBF scheme using all receiver antennas(ZFBF-WO-AS)when the base station adopts semi-orthogonal user selection(SUS)algorithm,and achieves larger throughput when the base station adopts the Round-robin scheduling algorithm.Compared with ZFBF-WO-AS,the proposed ZFBF-AS scheme can reduce the cost of user equipments and the channel state information requirement at the transmitter(CSIT)as well as the multiuser scheduling complexity at the transmitter.
文摘研究了(/%)0.023Al_(sol)、0.035Al_(sol)、0.018～0.019Al_(sol)-0.012～0.014Ti和0.019～0.020Al_(sol)-0.031～0.032Nb微合金化对60 t BOF-LF-VD-300 mm×360 mm CC-连轧工艺生产的Φ120 mm ZF7渗碳钢(/%:0.18～0.20C、0.22～0.25Si、1.22～1.30Mn、0.008～0.016P、0.019～0.029S、1.19～1.25Cr、0.001 8～0.002 2B)930℃加热时晶粒度混晶的影响。结果表明,在930℃7.5 h热处理条件下,当Al_(sol)为0.035%时ZF7钢未发生混晶现象,当钢中(/%)0.023Al_(sol)或0.018～0.019Al_(sol)-0.012～0.014Ti或0.019～0.020Al_(sol)-0.031～0.032Nb微合金化时,ZF7钢均发生了混晶现象,说明钢中有足够的Al_(sol)含量是防止ZF7钢发生混晶的关键因素。
