406 research outputs found
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
Measurement-based Channel Characterization Using Virtual Array with Directional Antenna
Obtaining accurate channel characteristics is essential for wireless communication system design and protocols. Directional scan sounding (DSS) achieved by rotating a directional antenna with a turntable, and virtual antenna array (VAA) basedsounding achieved by moving the antenna to the pre-designed locations are both popular methods to characterize static radio channel environments. However, the beam-width of the employed directional antenna limits the angular resolution of DSS. The conventional VAA usually employs an omnidirectional antenna which limits its application in millimeter wave bands due to the low antenna gain. In this work, VAA scheme based on directional antennas is presented to characterize the spatial-temporal profiles and omnidirectional pathloss of the channels. This scheme can provide high angular resolution and improve the SNR in the measurements simultaneously. Indoor channel measurements at 28 GHz with four different link distances were conducted to verify the effectiveness of the directional antenna based VAA scheme
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