LPC real-time speech transmission over 802.15.4

The IEEE 802.15.4 is one of the most used protocols for wireless sensor networks requiring long battery life and low data-rate, and it has been used for the most different applications. Nevertheless, few works address the audio transmission over 802.15.4. This paper focuses on the implementation of a vocal audio transmission over a 802.15.4 network. Due to the low data-rate provided by the protocol, the speech has been compressed using a Linear Predictive Coding (LPC) technique, which ensures a fair trade-off between quality and compression ratio. This paper contains a detailed analysis of the LPC vocoder parameters optimization and a simulation of the network using SystemC, with a particular attention on the quality of the compressed speech. The LPC vocoder has been implemented using Matlab and its quality has been measured using the PESQ algorithm.