Reliability, Latency, and Complexity Tradeoffs of Short Block Channel Codes for Narrowband Radio Channels

Abstract

Short-frame narrowband radio links require forward error correction that jointly balances reliability, decoding latency, and complexity. This paper compares a Long-Term Evolution (LTE) tail-biting convolutional code, the $\mathbf{5}^{\text {th }}$ Generation New Radio (5G NR) Low-Density Parity-Check (LDPC) code, and the 5G NR polar code under a paired Monte Carlo experiment with useful payloads of 300, 600, and 900 bits, code rates 1/2-3/4, and Gray coded Quaternary Phase Shift Keying (QPSK) over Additive White Gaussian Noise (AWGN) channel. All chains share the same payload, Cyclic Redundancy Check (CRC), transmitted length, and noise realization across 27 configurations, each bracketed within 0.1 dB. LDPC achieved the lowest required energy in six of nine cells and the lowest latency in all nine; polar coding led in three short, high rate cells. The results support 600 bits as a balanced reference operating point.