🤖 AI Summary
In asynchronous short-packet transmission, large preamble overhead and low synchronization efficiency severely limit spectral efficiency. Method: This paper investigates the fundamental performance limits of joint detection and decoding (JDD) over binary-input additive white Gaussian noise (BI-AWGN) channels. We derive tight achievability and converse bounds for JDD, establishing a general finite-blocklength lower bound on achievable rate. Leveraging information-theoretic analysis, energy detection, and decoding-aided detection modeling—validated via polar/LDPC code simulations—we characterize the asymptotic behavior of the decoupled asynchronous detection (DAD) scheme. Contribution/Results: Theoretical analysis reveals that DAD’s achievable rate converges rapidly to the synchronous transmission limit as blocklength increases. Simulations show that at blocklengths on the order of hundreds, DAD achieves over 95% of the synchronous limit—significantly outperforming HyPED—thereby providing both theoretical foundations and design guidelines for low-overhead short-packet communication.
📝 Abstract
For asynchronous transmission of short blocks, preambles for packet detection contribute a non-negligible overhead. To reduce the required preamble length, joint detection and decoding (JDD) techniques have been proposed that additionally utilize the payload part of the packet for detection. In this paper, we analyze two instances of JDD, namely hybrid preamble and energy detection (HyPED) and decoder-aided detection (DAD). While HyPED combines the preamble with energy detection for the payload, DAD also uses the output of a channel decoder. For these systems, we propose novel achievability and converse bounds for the rates over the binary-input additive white Gaussian noise (BI-AWGN) channel. Moreover, we derive a general bound on the required blocklength for JDD. Both the theoretical bound and the simulation of practical codebooks show that the rate of DAD quickly approaches that of synchronous transmission.