Design and Implementation of Spectrally Efficient Frequency Division Multiplexing Receiver

Abstract

Compared to orthogonal frequency division multiplexing (OFDM), spectrally efficient frequency division multiplexing (SEFDM) provides higher spectrum efficiency, which has been regarded as a promising waveform for future wireless communications. Against this background, the design of SEFDM receiver is investigated in this paper, considering its sampling frequency synchronization (SFS), timing synchronization, phase recovery, and detector design. Specifically, a two-step SFS module, which consists of a coarse sampling frequency offset (SFO) compensation and a frequency domain zero-forcing based fine estimation, is proposed first. Next, a low-complexity timing synchronization scheme is designed to avoid excessive multipliers and look-up-tables. Furthermore, an SFO-based phase recovery is proposed, which shares the compensation and SFO estimation with SFS module, thus further reducing the complexity of SEFDM receiver. Finally, TSVD-FSD based detector has been studied to efficiently eliminate intercarrier interference. Simulation results demonstrate the superiority of our proposed SEFDM receiver, where the transmission rate can be improved by 25% at a loss of only 0.7dB bit error ratio compared to OFDM. Finally, field programmable gate array (FPGA) based implementation is carried out to verify the effectiveness of our proposed SEFDM receiver in practice.INDEX TERMS Spectrally efficient frequency division multiplexing (SEFDM), sampling frequency synchronization (SFS), low-complexity implementation structure, field programmable gate array (FPGA)

An Energy-Efficient Carrier Synchronization Method for Galvanic Coupling Intra-Body Communication

“…Therefore, given the few algorithms for IBC-GC systems [10], [27], in Table VI,VII and Fig. 13 we have also compared the proposed solution with existing synchronization methods tested in AWGN-based channels [23], [25], [26], [39]. Table VI offers a more general overview of the SoA for research in synchronization for intra-body and over-the-air AWGN channels.…”

“…Another work [13] also analyzed the IBC system with very low error rate, but synchronization issues are not considered there since perfect synchronization is assumed a priori. In addition to IBC, Table VI includes conventional communication systems with synchronization solutions [25], [26], [39] applied for the same AWGN channel and E b /N 0 =10 dB. The Table compares both conventional signal processing and learning-based methods to estimate synchronization parameters.…”

“…While several synchronization methods have been studied and implemented in a variety of communication channels, including over-the-air [21], [22], satellite [23], and underwater links [24], considering both traditional methods and solution based on machine learning or deep learning [25], [26], few papers tackled this issue for GC intra-body channels [10], [27]. In most cases the authors sidestep the problem or assume perfect synchronization between transmitter and receiver [28] when implementing a GC transmission chain.…”

“…The sequences at the transmitter and receiver are normalized to the power P tx and P rx , where 2 /N depending on the considered modulation scheme. SNR is defined as the inverse of the error e c in (21).…”