Soft Combining ARQ Techniques for Wireless Systems Employing SC-FDE Schemes

SC-FDE with soft packet combining ARQ techniques for interference-limited UWB systems

“…The simplest way to design the receiver is by considering only the channel noise (i.e., by ignoring the interference in its design). In this case, the optimum feedforward coefficients for a given iteration, can be written as (see [18])…”

“…In this paper, we consider UWB systems employing SC-FDE techniques in the presence of strong interference signals that occupy a significant part of the transmission band and we consider soft combining ARQ schemes inspired in those proposed in [18]. It is shown that those techniques are not suitable to cope with strong interference signals, even when the receiver takes into account the interfering characteristics.…”

“…Moreover, we are not bounded by the performance of the basic code, since it is not a conventional punctured code. A promising soft combining ARQ technique for SC-FDE was proposed in [18], which was shown to be very efficient to cope with fading effects.…”

Delay Analysis for TDMA Schemes with Packet Recombining

“…We consider an uncoded scenario where the channels for each packet retransmission remains fixed. To allow an efficient packet separation we consider the cyclic-shifted versions of the FFT-blocks for each retransmission attempt which formally is equivalent to have cyclic-shifted versions of the channel in each retransmission attempt [3]. We assumed perfect synchronization and channel estimation conditions.…”

“…This limits the error correction capability to the base code capabilities. We proposed on [3] the use of soft packet combining techniques to implement H-ARQ on SC modulations (Single Carrier) with FDE (Frequency-Domain Equalization). It is based on repetition codes with soft decision, which is not bounded by the performance of the basic code.…”