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Channel estimation in rapidly time-varying or short and bursty communication scenarios is costly in terms of both pilot overhead and co-channel interference. In recent work, it was shown that multipath delay-diversity can be exploited to detect multiple co-channel user signals, provided that the relative multipath delays for the different users are distinct, and the two multipath ‘taps’ of each user have roughly commensurate power. These requirements may not hold naturally, however, especially for relatively narrowband or short-range transmissions with small delay spread. As an alternative, this paper advocates using dual antenna transmission in a manner that introduces artificial multipath and tight control of the power of the two channel taps, via baseband processing at the transmitter. The approach enjoys theoretical guarantees and affords simple decoding and accurate synchronization as a side bonus. Similar claims have been previously laid using packet repetition via a single transmit-antenna, but the dual-antenna artificial multipath scheme proposed herein doubles the transmission rate relative to packet repetition. Laboratory experiments using programmable radios are used to demonstrate successful operation of the proposed transmission scheme in practice.
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This content will become publicly available on July 7, 2026
Linearly Precoded Signal Alignment: How to Excise Interference with Little Rate Loss
How can we communicate reliably in the presence of unpredictable and potentially debilitating interference? As wireless communication becomes ever more ubiquitous, congestion and interference become increasingly inevitable, especially in contested scenarios. We have recently proposed a simple and practical method that uses packet repetition and multi-antenna reception to build two mixed signal and interference matrix views that contain the same packet in their span – in what we call signal alignment. This enables geometric/algebraic packet recovery via subspace intersection backed by theoretical guarantees – even in the face of adverse interference. A drawback is that the rate is halved owing to the repetition. This paper introduces a repetitionless signal alignment strategy that guarantees interference excision at controllable rate loss, which can be made practically negligible. This new family of signal alignment schemes is based on judicious linear precoding that can also be combined with error control coding. Various precoder designs are introduced and the redundancy split between the linear precoder and the Galois field (error control) encoder is considered in simulations to assess the right trade-off between interference excision and fading / random error control.
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- Award ID(s):
- 2433870
- PAR ID:
- 10650483
- Publisher / Repository:
- IEEE
- Date Published:
- Page Range / eLocation ID:
- 1 to 5
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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