Impact Analysis of Directional Antennas and Multiantenna Beamformers on Radio Transmission

• Published in: IEEE transactions on vehicular technology Vol. 57; no. 3; pp. 1695 - 1707
• Main Authors: Haibing Yang, Herben, M.H.A.J., Akkermans, I.J.A.G., Smulders, P.F.M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Antennas; Antennas and propagation; Applied sciences; Array signal processing; Channels; Conventional beamforming; Delay; Detection, estimation, filtering, equalization, prediction; Directional antennas; Directive antennas; double-directional channel; Exact sciences and technology; Frequency; Gain; half-power beamwidth (HPBW); Information, signal and communications theory; Mathematical analysis; Mathematical models; multiantenna beamforming; Radiocommunications; Receivers; Rician channels; Rician K -factor; root-mean-squared (rms) delay spread (RDS); Signal and communications theory; Signal, noise; Spectra; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Transmitters. Receivers; Transmitting antennas; double-directional channel; RMS delay spread; Conventional beamforming; half-power beamwidth; multi-antenna beamforming; Rician K-factor; Fading channels; Parameter estimation; half-power beamwidth (HPBW); System design; Rice fading; Receiver; Information transmission; multiantenna beamforming; Beam forming; Directive antenna; Time domain method; Channel estimation; Radio transmission; Delay time; root-mean-squared (rms) delay spread (RDS); Root mean square value; Alignment defect; Gain; Quantitative analysis; Antenna radiation patterns; Signal to noise ratio
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2007.907308

The impact of directional antennas and multiantenna beamformers on radio transmission is formulated in terms of the gain of the Rician -factor, the reduction of the root-mean-squared delay spread, and the gain of the signal-to-noise ratio at the receiver for Rician fading channels in multipath environments. The analysis is based on a double-directional channel model. For the analytical formulation, the joint channel spectrum is assumed to be decomposable into separate spectra in time and angular domains. By way of illustration, closed-form expressions for the impact of hypothetical cosine-shaped antenna patternsand conventional beamformers are derived for channels with uniform angular spectra and an exponential decaying delay spectrum. The impact factors are explicitly related to the antenna beamwidth and the number of antenna elements. In addition, the effect of misalignment between the antenna main beam and the direct path is included in the analysis. The quantitative analysis given in this paper is important for radio system design, particularly for the design of antennas and multiantenna beamformer configurations.