Abstract
We propose a Line-coding scheme that jointly performs modulation and channel coding by mapping K information bits to N symbols with m active positions per block of information data. The mapping preserves over the block of data and creates a sparse near-orthogonal codebook that increases the Euclidean distance between the transmitted codewords, which improves the detection performance when Maximum-likelihood (ML) demodulation / detection is utilized at the receiver. For a fair comparison, the spectral efficiency (SE) of proposed scheme is kept at 1 bit/symbol, and is compared with Binary Phase Shift Keying (BPSK) the optimum modulation from power efficiency perspective in a single input single output (SISO) channel and it is shown that the proposed scheme provides signal to noise (SNR) gain of 1 dB over BPSK at a Bit Error-Rate (BER) of 10-5 in Additive White Gaussian Noise (AWGN) channel, and 7dB in uncorrelated frequency-flat Rayleigh fading at a BER ≈ 10-4. The proposed scheme is then combined with 5 th Generation (5G) New Radio (NR) Low-density Parity check (LDPC) codes, and it is shown that proposed scheme provides SNR gain ≈ 1.2 dB over BPSK-LDPC at high code rates (such as 0.61) in an AWGN channel while also reducing the decoder floating-point operations by 25%. However, in low code rate (e.g. 0.33) scenarios, the proposed scheme is inferior to the BPSK-LDPC scheme but still retains lower complexity (about 20% less floating-point operations) that BPSK-LDPC suggesting that the proposed scheme is more appropriate for high code-rate applications.