Elevation and azimuth-aided channel estimation scheme for airborne hyperspectral data transmission

Abstract

A channel-estimation (CE) scheme is proposed to estimate the complex amplitude, Doppler shift, angle-of-departure, and angle-of-arrival of the channel taps for sparse and doubly selective channels for hyperspectral image transmission from unmanned aircraft vehicles (UAVs) to ground stations. The proposed method is dubbed as compressed-sensing joint parameter estimation (CS-JPE) and finds the channel parameters matrix by employing a compressed-sensing (CS)-based method. Afterward, a modified version of the joint parameter estimation (JPE) is proposed as CS-JPE and is dubbed as M-CS-JPE, which employs the elevation-azimuth angles of the line-of-sight channel tap to estimate the channel parameters with higher accuracy and lower computational complexity compared to the CS-JPE scheme. For higher accuracy of the M-CS-JPE, an elevation-azimuth angle estimation is proposed and is dubbed as fractal-structurearray since it uses a fractal structure for the placement of the UAV antennas. The performance of the CE methods is appraised by simulating transmission of AVIRIS hyperspectral data via the communication channel and evaluating their accuracy for the classification after demodulation. Compared to the least-square method, the simulation results indicate up to 30-dB figure of merit in the bit-error-rate and 10 times improvement in the hyperspectral image classification fidelity.

Downlink data transmission for high‐speed trains in 5G communication systems

“…As a result, if MUSIC is going to be used for DSF estimation, a fine‐grained DSF search (DSFS) – the frequencies for which are constructed in (10) – should be employed. However, as it is indicated in [13], the CC of MUSIC increases with the increment of the DSFS step. Since the antennas are highly directional and have low beamwidth in high carrier frequency of the 5G communication systems, the CC of MUSIC would be decreased considerably if the DSFS procedure is only done for the DSFs that correspond to the angles which are limited in the transmitter antenna beamwidth. Denote the LoS angle between the BS and HST as and the BS antenna beamwidth as BW .…”

“…As a result, if MUSIC is going to be used for DSF estimation, a fine‐grained DSF search (DSFS) – the frequencies for which are constructed in (10) – should be employed. However, as it is indicated in [13], the CC of MUSIC increases with the increment of the DSFS step.…”