I. INTRODUCTION The interaction of the atoms in a solid leads to the vibration of atoms around their equilibrium position and hence the lattice waves with various modes. Debye.analysed the energy of the lattice vibrat...I. INTRODUCTION The interaction of the atoms in a solid leads to the vibration of atoms around their equilibrium position and hence the lattice waves with various modes. Debye.analysed the energy of the lattice vibration basing on the consideration of the elastic waves in the展开更多
Coherent detection in OFDM systems requires accurate channel state information (CSI) at the receiver. Channel estimation based on pilot-symbol-assisted transmissions provides a reliable way to obtain CSI. Use of pilot...Coherent detection in OFDM systems requires accurate channel state information (CSI) at the receiver. Channel estimation based on pilot-symbol-assisted transmissions provides a reliable way to obtain CSI. Use of pilot symbols for channel estimation, introduces overhead and it is desirable to keep the number of pilot symbols as minimum as possible. This paper introduces a new tight bound for the number of pilots in channel estimation using adaptive scheme in OFDM systems. We calculate the minimum number of necessary pilots using two approaches. The first approach for the number of pilots is obtained based on Doppler frequency shift estimation and the second approach is acquired based on channel length estimation using second order statistics of received signal. Finally we obtain the tight bound for the number of pilots using attained values.展开更多
文摘I. INTRODUCTION The interaction of the atoms in a solid leads to the vibration of atoms around their equilibrium position and hence the lattice waves with various modes. Debye.analysed the energy of the lattice vibration basing on the consideration of the elastic waves in the
文摘Coherent detection in OFDM systems requires accurate channel state information (CSI) at the receiver. Channel estimation based on pilot-symbol-assisted transmissions provides a reliable way to obtain CSI. Use of pilot symbols for channel estimation, introduces overhead and it is desirable to keep the number of pilot symbols as minimum as possible. This paper introduces a new tight bound for the number of pilots in channel estimation using adaptive scheme in OFDM systems. We calculate the minimum number of necessary pilots using two approaches. The first approach for the number of pilots is obtained based on Doppler frequency shift estimation and the second approach is acquired based on channel length estimation using second order statistics of received signal. Finally we obtain the tight bound for the number of pilots using attained values.
