Reduced-complexity hybrid time/frequency channel estimation for DVB-H

Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H) which is required to operate under high mobility conditions resulting in significant Inter-Carrier Interference (ICI). Under these conditions, the conventional one-tap per subcarrier channel estimation and equalization is suboptimal since it does not account for ICI effects. A hybrid frequency and time-domain channel estimation method was developed in [1] to mitigate the ICI due to time-variation within one OFDM symbol. We show that significant additional complexity reductions can be achieved by exploiting the special structure of the channel matrix over both the time and frequency domains. Our simulation results show that the proposed method has much less complexity with small performance loss under fast-varying channel conditions for DVB-H system.