Experimental studies of direction of arrivals using a smart antenna testbed in wireless communication systems

Abstract

SUMMARYThis paper presents some preliminary results from experimental studies on space-division-multiple-access (SDMA) for wireless communications. A smart antenna system utilizing direction-of-arrival (DOA)-based beamforming techniques can enhance signal quality by reducing co-channel interference from mobiles located at angles spatially distinct from the base station. Adopting both smart uplink and downlink beamforming, a communication system with an antenna array can increase the cell coverage of a base station and significantly boost capacity compared with conventional antenna systems. However, successful implementation of DOA-based beamforming techniques depends on the DOA characteristics. This paper presented the feasibility of direction finding and DOA variation with respect to frequency. Furthermore, the angle spread was studied for selected environments. The results demonstrate the feasibility of applying proposed smart antenna system utilizing DOA-based beamforming algorithm for increasing channel capacity and improving system performance in frequency-division-duplex (FDD) wireless communication systems.

An improved MMUSIC algorithm of direction of arrival estimation

“…Moreover, as the signals correlate or become close, the peaks combine [7]. Figure 1 shows that N plane signals impinge on the M -element uniform linear array, where d is the element distance, and  i is the direction angle vector of the ith signal [8][9][10][11]. Figure 1 shows that N plane signals impinge on the M -element uniform linear array, where d is the element distance, and  i is the direction angle vector of the ith signal [8][9][10][11].…”

“…To develop the advantage on the ability to distinguish all kinds of receiving signals with low computational complexity, the array model of MMUSIC algorithm is first introduced in Figure 1. Figure 1 shows that N plane signals impinge on the M -element uniform linear array, where d is the element distance, and  i is the direction angle vector of the ith signal [8][9][10][11].…”

A simple design of planar microstrip antenna on composite material substrate for Ku/K band satellite applications

“…Some of the inherited properties of the microstrip antennas such as low profile characteristics, light weight, ease of realization and less complex integration competence to other components of the system lend to their attractiveness [1][2][3]. Further compactness and portability are achieved by designing the antenna module for multiple operating frequencies which takes up less space by replacing single frequency multiple antennas.…”

“…The microstrip patch antenna is one of the preferred choices for wireless/satellite communications to accommodate dual frequency bands. Some of the inherited properties of the microstrip antennas such as low profile characteristics, light weight, ease of realization and less complex integration competence to other components of the system lend to their attractiveness [1][2][3]. However, the microstrip antennas also offer some demerits like spurious feed radiation, higher cross polarization and narrow bandwidth that needs to improve through the application of efficient technique and/or design.…”

Modular Software-Defined Radio Testbed for Rapid Prototyping of Localization Algorithms

“…The early prototypes operated at relatively low frequencies, used bulky antennas, had narrow bandwidths [3] and comprised specialised digital signal processing (DSP) hardware [4]. Most of the systems created in the early 2000s were designed and tuned for specific applications and techniques [5], [6]. Only relatively recently with the advancement of general purpose computing have there been testbeds that provide greater flexibility [7], [8].…”