A semiblind demodulator aided by protocols for wireless ATM network

In this paper, we study the demodulation problem in time-division-multiple-access (TDMA) wireless asynchronous transfer mode (ATM) networks. We propose a self-organizing-map (SOM) based demodulator. A linear interpolation with decision feedback (LIDF) combined with SOM algorithm (LIDF-SOM) is developed, in which the SOM network is initialized with some known symbols. Such known symbols are obtained by exploiting the medium access control (MAC) and data link control (DLC) protocols. Our scheme has three advantages, it: (1) avoids training symbols for uplink data bursts, (2) has reduced computational costs compared with common blind demodulators, and (3) blocks propagation estimation error through cells. Simulation results show that LIDF-SOM has better performances (0.2-0.4 dB gain) over time-varying channel as compared to the LIDF algorithm.