IEEE Transactions on Signal Processing · 2002 · 109 citations · 9 references
EngineeringElectrical EngineeringAntennasMicrowave EngineeringWireless CommunicationsAntenna ArraysAntenna DesignAntenna SimulationBeamformingMicrowave AntennasSmart AntennasAntenna AnalysisAntenna Array DesignAntenna Element SpacingArray DesignFiltersFractional BandwidthSmart Antenna DesignWideband Antennas
Smart antenna techniques at the base station can dramatically improve mobile radio system performance by employing spatial filtering. The paper proposes a fully spatial signal processor based on a rectangular array configuration. The authors implement two‑dimensional spatial filters using microstrip‑based rectangular arrays that provide wideband angular and frequency filtering, and they propose two algorithms for computing real‑valued element weights to compensate for non‑omnidirectional or frequency‑dependent element responses. Simulation results show that the proposed beamformers achieve satisfactory frequency selectivity, with the first algorithm delivering sharper, more controlled beams and the second offering a simpler, wider beam with lower fractional bandwidth.
Smart antenna techniques at the base station can dramatically improve the performance of the mobile radio system by employing spatial filtering. The design of a fully spatial signal processor using rectangular array configuration is proposed. Two-dimensional (2-D) spatial filters that can be implemented by microstrip technology are capable of filtering the received signal in the angular domain as well as the frequency domain. Furthermore, it has wideband properties and, hence, eliminates the requirement of different antenna spacing for applications including various carrier frequencies. The desired frequency selectivity of the smart antenna can be combined with compensation of the undesired frequency performance of a single antenna element, and the result is quite satisfactory for practical implementation. In addition, if the elements of the array are not perfectly omnidirectional or frequency independent, we can compensate for these deficiencies in the design algorithm. Two different algorithms for calculating the real-valued weights of the antenna elements are proposed. The first algorithm is more complex but leads to sharper beams and controlled performance. The second method is simpler but has wider beam and lower fractional bandwidth. Some computer simulation results demonstrating the directional beam patterns of the designed beamformers are also presented.
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