The optimization of pilot symbol parameters can improve the spectral efficiency of adaptive
modulation for orthogonal frequency division multiplexing (OFDM) systems, since pilot …

Optimal pilot design is an important issue for OFDM systems since the pilot tones
significantly affect channel estimation performance. Unlike the conventional approaches …

We compare diverse frequency-domain multiplexed pilot arrangement schemes for time-
varying channel estimation in an orthogonal frequency-division multiplexing (OFDM) system …

Orthogonal frequency division multiplexing (OFDM) is a multi-carrier transmission
technology in wireless environment, and can also be seen as a multi-carrier digital …

The performance of channel estimation in OFDM systems significantly depends on the pilot
signal, which is usually scattered in the time and frequency domains. For a given pilot …

Pilot design significantly affects the performance of channel estimation. Optimum pilot
design for fully loaded OFDM systems has been well studied. In the practical case of OFDM …

The problem of training symbol placement and power for the channel estimation of OFDM
over block-fading channel in the presence of null subcarriers is considered. We use convex …

A novel, reduced complexity iterative channel estimation algorithm for OFDM systems using
superimposed pilots is proposed. It utilizes past channel estimations of double correlated …

The channel estimation methods for OFDM systems based on a comb-type pilot sub-carrier
arrangement are investigated. The channel estimation algorithm based on comb-type pilots …

We find that placing each pilot tone in an equally spaced manner according to the
conventional placement scheme is not suitable for doubly selective channel estimation. In …