Delayed Decision feedback equalization with adaptive noise filtering for IEEE 802.11p

In this paper a receiver making use of a complexity-optimized Decision feedback equalization (DFE) structure and adaptive noise filtering is presented. Vehicular transmission systems such as IEEE 802.11p are facing serious challenges originating from the vehicular channel. Due to the channels high Doppler frequencies and long path delays, channel estimation and equalization is a pivotal aspect of the receiver structure. Consequently, a wide variety of tracking concepts have been proposed to tackle the challenge of these time- and frequency-selective channels, ranging from the introduction of additional pilots to complex message passing algorithms. DFE inarguably allows best tracking of the channel´s impulse response but is often rejected due to its alleged computational complexity. With the proposed Delayed DFE receiver concept, complex buffering structures are avoided while already existent transmitter structures can be reused. Due to the high precision of the obtained channel state information, further optimization can be applied to adaptively suppress channel noise.