Delayless Robust DPCM Audio Transmission for Digital Wireless Microphones

摘要

The employment of digital wireless microphones in professional contexts requires ultra-low delay, strong robustness, and high audio quality. On the other hand, audio coding is required in order to comply with the restrictions on the bandwidth of the radio channel, making the resulting source-coded audio signal more vulnerable to channel distortions. Therefore, in this work we present a transmission system for differential pulse-code modulated (DPCM) audio with receiver-sided soft-decision error concealment exploiting channel reliability information, explicit redundancy by simple delayless parity-check codes, and residual redundancy within the source-coded audio signal. Simulations on frequency-shift keying (FSK)-modulated channels with additive white Gaussian noise show considerable gains in audio quality compared to hard-decision decoding and soft-decision decoding only exploiting reliability information and Oth-order a priori knowledge.