LTI Transceivers With Reduced Redundancy

Abstract

This paper presents new linear time-invariant (LTI) block-based transceivers which employ a reduced amount of redundancy to eliminate the interblock interference. The proposals encompass both multicarrier and single-carrier systems with either zero-forcing or minimum mean-square error (MSE) equalizers. The amount of redundancy ranges from the minimum, 2 , to the most commonly used value, , assuming a channel-impulse response of order . The resulting transceivers allow for superfast equalization of the received data blocks, since they only use fast Fourier transforms and single-tap equalizers in their structures. The paper also includes an MSE analysis of the proposed transceivers with respect to the amount of redundancy. Indeed, we demonstrate that larger amounts of transmitted redundant elements lead to lower MSE of symbols at the receiver end. Computer simulations indicate that, by choosing an appropriate amount of redundancy, our proposals can achieve higher throughputs than the standard superfast multicarrier and single-carrier systems, while keeping the same asymptotic computational complexity for the equalization process.

Faster-Than-Nyquist Signaling Via Spatiotemporal Symbol-Level Precoding for Multi-User MISO Redundant Transmissions

“…max < 2M is assumed to be an even integer w.l.o.g. In order to deal with the IBI possibly harmful effects, we propose the use of redundant zero-padding zero-jamming (ZP-ZJ) transceivers [23,24,25,26,27] with an adjustable amount of redundant elements which are added and removed through the multiplication by the matrices (see Figs. 1 and 2…”

“…In this work we propose a framework for addressing the FTNrelated IBI effects in spatiotemporal SLP schemes by adapting to the non-linear setup some well-known ideas from reduced-redundancy linear transceivers [22,23,24,25,26,27]. The resulting spatiotemporal precoders allow for the trade-off between constructive and destructive IBI effects, and generalize the proposals from [20,21].…”

“…In this work, we address this open problem by proposing a new MU-MISO system model that tackles the frequency-selectivity-related IBI, ISI, and ICI effects using space-time-frequency SLPs. We adapt to the non-linear setup some ideas from reduced-redundancy linear transceivers [27], [28], [29], [30], [31], [32], [33], and design redundant space-time-frequency SLPs that minimize the total transmit power while allowing for the trade-off between constructive and destructive IBI effects. The amount of added redundancy may vary from zero (full IBI) to half (destructive IBIfree) the group delay of the equivalent channel model.…”

Block Transceivers: OFDM and Beyond

“…In fact, the authors in [54] have proved mathematically that the MSE performance of reduced-redundancy transceivers degrades as the number of transmitted redundant elements reduces. Nevertheless, we should note that ZP-ZJ systems do not necessarily outperform OFDM-based transceivers.…”

Frequency-Packed Faster-Than-Nyquist Signaling via Symbol-Level Precoding for Multiuser MISO Redundant Transmissions

“…However, the backward IBI of 538 the current block toward the previous one is still destructive 539 since the previous one has been already designed. 540 Thus, in order to deal with the backward IBI harmful 541 effects, we propose the use of redundant zero-padding zero-542jamming (ZP-ZJ) transceivers[24],[28],[30],[32],[33] with 543 an adjustable amount of redundant elements which are added 544 and removed through the multiplication by the matrices…”