I don't know a lot about comm system design.
I have an AWGN channel and low SNR (-3dB). Bandwidth is constrained to some maximum, B. I would like to know good choices of modulation and coding to maximize throughput.
I've read that restriction to binary modulation at low SNR does not degrade capacity wrt to log_2(1 + SNR), but that coding is necessary and that B needs to be big.
I've also read that low-rate linear binary codes can achieve capacity. Is there a particular code family I should use for my scenario?