An Experimental Study on Indoor Massive 3D-MIMO Channel at 30-40 GHz Band

Three-dimensional (3D) multiple-input multiple-output (MIMO) channel sounder measurements are producposed for a multi-user MIMO channel at the 30-40 GHz mm-wave band. A 3D-MIMO downlink transmissions links withto two users is considered. The measurement campaign employing a vector network analyzer (VNA) washas been performed in an indoor office scenario. Based on the measurement results, weThe characterizeations of mm-wave 3D-MIMO channels are performed in the wavenumber domain and the time domain, which are jointly analyzed via a 3D inverse fast Fourier transform (IFFT). Measurement shows that the massive 3D-MIMO has a significant improvement on resolution of multipathes beyond none-massive 3D-MIMO

Impact of imperfect angle estimation on spatial and directional modulation

In this paper, we investigate the impact of imperfect angle estimation (IAE) on spatial and directional modulation (SDM) systems, assuming that the signal experiences line of sight (LoS) propagation. In SDM systems with IAE, the variation is analyzed in detail, when there is a mismatch between the beamforming and precise channel matrices. Based on the union bound and statistics theory, the average bit error probabilities (ABEPs) for both the legitimate user and eavesdropper are derived. In addition, the ergodic rate is also quantified with IAE. Simulation results are presented to show that the achieved theoretical ABEPs are useful in quantifying the potential performance penalty. We also show that the mismatch between the beamforming and precise channel matrices will become greater with the increase in direction measurement error (DME), which affects the detection for both the legitimate user and eavesdropper. On the other hand, due to the effect of IAE, the SDM requires more signal-to-noise ratio (SNR) gain to achieve a stable ergodic secrecy rate

Near-field Ultra-wideband mmWave Channel Characterization Using Successive Cancellation Beamspace UCA Algorithm

Of the wide palette of 5G features, ultra-wide bandwidth and large-scale antenna configuration are regarded as the essential enabling technology components at millimeter wave (mmWave) communication. Accurate knowledge of delay and angle information of multipath components is essential for many applications in mmWave systems. There is a strong need for a low computation-cost channel estimation algorithm for such systems, where typically adopted far-field and narrowband assumptions might be violated. In this work, a generic yet novel beamspace uniform circular array (UCA) beamforming algorithm with successive cancellation scheme is proposed to jointly detect the impinging angle and delay of the multipath components. The proposed algorithm is computationally cheap and it works for ultra-wideband (UWB) systems in the near-field conditions. Both numerical simulations and experimental validation results are provided to demonstrate the effectiveness and robustness of the proposed algorithm, compared to the state-of-art works