在宽带高精度光子模数转换(Photonic Analog-to-Digital Converter,PADC)系统中,频综模块主要用于驱动PADC系统中的光开关阵列来实现并行解复用功能。介绍了PADC系统中的频综模块设计与实现,通过优化设计频综模块的内部器件可以调节光...在宽带高精度光子模数转换(Photonic Analog-to-Digital Converter,PADC)系统中,频综模块主要用于驱动PADC系统中的光开关阵列来实现并行解复用功能。介绍了PADC系统中的频综模块设计与实现,通过优化设计频综模块的内部器件可以调节光开关阵列的并行解复用性能,从而改善PADC系统的量化有效比特位数(Effective Number of Bits,ENOB)。实验对比分析了不同频综模块结构对PADC系统性能的影响,在9.812GHz的微波信号输入下的量化ENOB达7.73位,证明了频综模块优化设计方案的有效性。展开更多
This paper investigates the achievable uplink spectral efficiency(SE) of a massive multi-input multi-output(MIMO) system with a mixed analog-to-digital converter(ADC) receiver architecture, in which some antennas are ...This paper investigates the achievable uplink spectral efficiency(SE) of a massive multi-input multi-output(MIMO) system with a mixed analog-to-digital converter(ADC) receiver architecture, in which some antennas are equipped with full-resolution ADCs while others are deployed with low-resolution ADCs. We derive the theoretical results and corresponding approximate expressions of the achievable SE in multi-cell systems with maximum ratio combining(MRC) detector and in single-cell systems with zero-forcing(ZF) detector. Based on approximated results, the effects of physical parameters, including the transmit power, the number of antennas, the proportion of full-resolution ADCs and the quantization precision of the low-resolution ADCs on the achievable SE are revealed. Furthermore, we propose the power allocation algorithms based on the lower bound and upper bound of approximate achievable SE. Our results show that the total achievable SE improves by increasing the number of BS antennas, the signal-to-noise ratio(SNR), and the quantization precision. Results showcase that proposed power allocation algorithms remarkably improve the total achievable SE comparing to the equal power allocation algorithm, which verifies the effectiveness of our proposed schemes.展开更多
The uplink achievable rate of massive multiple-input-multiple-output(MIMO) systems, where the low-resolution analog-to-digital converters(ADCs) are assumed to equip at the base station(BS), is investigated in this pap...The uplink achievable rate of massive multiple-input-multiple-output(MIMO) systems, where the low-resolution analog-to-digital converters(ADCs) are assumed to equip at the base station(BS), is investigated in this paper. We assume that only imperfect channel station information is known at the BS. Then a new MMSE receiver is designed by taking not only the Gaussian noise, but also the channel estimation error and quantizer noise into account. By using the Stieltjes transform of random matrix, we further derive a tight asymptotic equivalent for the uplink achievable rate with proposed MMSE receiver. We present a detailed analysis for the number of BS antennas through the expression of the achievable rates and validate the results using numerical simulations. It is also shown that we can compensate the performance loss due to the low-resolution quantization by increasing the number of antennas at the BS.展开更多
文摘在宽带高精度光子模数转换(Photonic Analog-to-Digital Converter,PADC)系统中,频综模块主要用于驱动PADC系统中的光开关阵列来实现并行解复用功能。介绍了PADC系统中的频综模块设计与实现,通过优化设计频综模块的内部器件可以调节光开关阵列的并行解复用性能,从而改善PADC系统的量化有效比特位数(Effective Number of Bits,ENOB)。实验对比分析了不同频综模块结构对PADC系统性能的影响,在9.812GHz的微波信号输入下的量化ENOB达7.73位,证明了频综模块优化设计方案的有效性。
基金supported in part by the National Science Foundation(NSFC)for Distinguished Young Scholars of China with Grant 61625106the National Natural Science Foundation of China under Grant 61531011+1 种基金the Hong Kong,Macao and Taiwan Science and Technology Cooperation Program of China(2016YFE0123100)the Guangzhou University project under Grant 27000503123
文摘This paper investigates the achievable uplink spectral efficiency(SE) of a massive multi-input multi-output(MIMO) system with a mixed analog-to-digital converter(ADC) receiver architecture, in which some antennas are equipped with full-resolution ADCs while others are deployed with low-resolution ADCs. We derive the theoretical results and corresponding approximate expressions of the achievable SE in multi-cell systems with maximum ratio combining(MRC) detector and in single-cell systems with zero-forcing(ZF) detector. Based on approximated results, the effects of physical parameters, including the transmit power, the number of antennas, the proportion of full-resolution ADCs and the quantization precision of the low-resolution ADCs on the achievable SE are revealed. Furthermore, we propose the power allocation algorithms based on the lower bound and upper bound of approximate achievable SE. Our results show that the total achievable SE improves by increasing the number of BS antennas, the signal-to-noise ratio(SNR), and the quantization precision. Results showcase that proposed power allocation algorithms remarkably improve the total achievable SE comparing to the equal power allocation algorithm, which verifies the effectiveness of our proposed schemes.
基金supported by the Beijing Natural Science Foundation under Grant No. L172030the Beijing Municipal Natural Science Foundation under Grant No. 4174102+2 种基金NSFC Project under Grants No. 61471027the National Natural Science Foundation of China under Grant No. 61701017 and Grant No. 61601018the Open Research Fund through the National Mobile Communications Research Laboratory, Southeast University, under Grant No. 2017D01
文摘The uplink achievable rate of massive multiple-input-multiple-output(MIMO) systems, where the low-resolution analog-to-digital converters(ADCs) are assumed to equip at the base station(BS), is investigated in this paper. We assume that only imperfect channel station information is known at the BS. Then a new MMSE receiver is designed by taking not only the Gaussian noise, but also the channel estimation error and quantizer noise into account. By using the Stieltjes transform of random matrix, we further derive a tight asymptotic equivalent for the uplink achievable rate with proposed MMSE receiver. We present a detailed analysis for the number of BS antennas through the expression of the achievable rates and validate the results using numerical simulations. It is also shown that we can compensate the performance loss due to the low-resolution quantization by increasing the number of antennas at the BS.
