Millimeter wave receive beamforming with one-bit quantization

Nowadays,the increase amounts of mobile data has resulted in great demand on existing communication networks.The millimeter-wave band offers large bandwidths to be exploited,which eases the spectrum crunch for bands below 3 GHz.In order to mitigate the path loss from high frequencies,a large antenna array and beamforming technology are adopted to increase the link gain.However,a challenge arises from the new band.Given the order of gigahertz bandwidth and the high sampling rate,the high-resolution ADC(Analog-to-Digital Converter)used in the large array creates a power consumption bottleneck.One solution is to use a low-resolution ADC to replace the full-precision ADC.In this paper,we propose a mixed LMS(Least Mean Square)receiver beamforming method for a millimeter-wave one-bit antenna array.We first use a grid-based approach to roughly estimate the DOA(Direction of Arrival)of the incoming signal.Then,we use the steering vector for the DOA as an initial value for the LMS method.A simulation shows that our proposed mixed LMS receiver beamforming method for the one-bit antenna array attains a performance level near the optimal one that obtained with an accurate DOA.The radiation pattern of the mixed LMS method almost overlaps the pattern for the accurate DOA,and the spectral efficiency of the mixed LMS method reach up with that obtained from accurate DOA.Furthermore,owing to the use of initial values from rough DOA estimation,the mixed LMS method has a fast convergence.