Author(s): Ohno Shuichi | Manasseh Emmanuel | Nakamoto Masayoshi
Journal: EURASIP Journal on Wireless Communications and Networking
ISSN 1687-1472
Volume: 2011;
Issue: 1;
Start page: 2;
Date: 2011;
Original page
Keywords: Orthogonal frequency division multiplexing (OFDM) | Channel estimation | Semidefinite programming (SDP) | Convex optimization | Pilot symbols | Pilot design
ABSTRACT
Abstract In this article, design of preamble for channel estimation and pilot symbols for pilot-assisted channel estimation in orthogonal frequency division multiplexing system with null subcarriers is studied. Both the preambles and pilot symbols are designed to minimize the l 2 or the l ∞ norm of the channel estimate mean-squared errors (MSE) in frequency-selective environments. We use convex optimization technique to find optimal power distribution to the preamble by casting the MSE minimization problem into a semidefinite programming problem. Then, using the designed optimal preamble as an initial value, we iteratively select the placement and optimally distribute power to the selected pilot symbols. Design examples consistent with IEEE 802.11a as well as IEEE 802.16e are provided to illustrate the superior performance of our proposed method over the equi-spaced equi-powered pilot symbols and the partially equi-spaced pilot symbols.
Journal: EURASIP Journal on Wireless Communications and Networking
ISSN 1687-1472
Volume: 2011;
Issue: 1;
Start page: 2;
Date: 2011;
Original page
Keywords: Orthogonal frequency division multiplexing (OFDM) | Channel estimation | Semidefinite programming (SDP) | Convex optimization | Pilot symbols | Pilot design
ABSTRACT
Abstract In this article, design of preamble for channel estimation and pilot symbols for pilot-assisted channel estimation in orthogonal frequency division multiplexing system with null subcarriers is studied. Both the preambles and pilot symbols are designed to minimize the l 2 or the l ∞ norm of the channel estimate mean-squared errors (MSE) in frequency-selective environments. We use convex optimization technique to find optimal power distribution to the preamble by casting the MSE minimization problem into a semidefinite programming problem. Then, using the designed optimal preamble as an initial value, we iteratively select the placement and optimally distribute power to the selected pilot symbols. Design examples consistent with IEEE 802.11a as well as IEEE 802.16e are provided to illustrate the superior performance of our proposed method over the equi-spaced equi-powered pilot symbols and the partially equi-spaced pilot symbols.
