Adaptive bit loading with reduced computational time and complexity for multicarrier wireless communications

This correspondence presents an efficient bit loading technique that enables reduction of the time and computational complexity requirements for mobile wireless multicarrier communications, while satisfying certain bit-error-rate constraints. The complexity reduction is achieved by exploiting the channel correlation to reduce the number of subcarriers involved in the bit loading process, and consequently, the required computational time is reduced significantly. The computational complexity of the bit allocation process can be designed to match the system computational capabilities by deriving a theoretical upper bound on the average number of subcarriers involved in the bit loading process. The obtained results demonstrate that the proposed bit loading process time complexity is only 14% of conventional techniques at the signal-to-noise ratio of 20 dB with a throughput loss of about 13%.