Direction of Estimation
Abstract: In wireless communication using omnidirectional antennas communication is made in directions not pointing towards the recipient resulting in energy waste, and producing traffic collisions and reducing the battery life. One way of reducing this problem is to use of smart antenna that uses selectable radiation patterns depending on the situations. These antennas provide the ability to sense the direction of incoming signals. Smart antennas are the antenna arrays with smart signal processing algorithms used to identify spatial signal signature such as the Direction of arrival (DOA) and used to calculate the beam forming vectors, to tract and locate the antenna beam on the mobile/target. Smart has the main function of DOA estimation.
Keywords: Smart antenna, DOA ,Wireless communication.
1. Introduction: The smart antenna system estimates the direction of arrival of the signal, using techniques such as MUSIC (Multiple Signal Classification), estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithms. They Involve finding a spatial spectrum of the antenna/sensor array, and calculating the
DOA from the peaks of this spectrum. These calculations are computationally intensive.
2.Direction Of arrival Estimation Algorithms
The array-based direction-of-algorithm estimation techniques can be broadly divided into four different types conventional techniques, subspace based techniques, maximum likelihood techniques and the integrated techniques which combine property restoral techniques with subspace based techniques. Conventional methods are based on classical beam forming techniques and require a large number of elements to achieve high resolution. Subspace based methods are high resolution sub-optimal techinques which exploit the eigen structure of the input data matrix. Maximum likelihood techniques are optimal techniques which can perform well even under low signal-to-noise ratio conditions, but are in general computationally
Keywords: Smart antenna, DOA ,Wireless communication.
1. Introduction: The smart antenna system estimates the direction of arrival of the signal, using techniques such as MUSIC (Multiple Signal Classification), estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithms. They Involve finding a spatial spectrum of the antenna/sensor array, and calculating the
DOA from the peaks of this spectrum. These calculations are computationally intensive.
2.Direction Of arrival Estimation Algorithms
The array-based direction-of-algorithm estimation techniques can be broadly divided into four different types conventional techniques, subspace based techniques, maximum likelihood techniques and the integrated techniques which combine property restoral techniques with subspace based techniques. Conventional methods are based on classical beam forming techniques and require a large number of elements to achieve high resolution. Subspace based methods are high resolution sub-optimal techinques which exploit the eigen structure of the input data matrix. Maximum likelihood techniques are optimal techniques which can perform well even under low signal-to-noise ratio conditions, but are in general computationally