Implementation and evaluation of low-speed speech compression LPC and MELP algorithms

Abstract

Abstract— Currently, the design of a speech signal compression module that responds to low speed but still ensures signal quality for communication devices is a topic of interest for research. LPC (Linear Prediction Coding) and MELP (Mixed-Excitation Linear Prediction), two common approaches, are extensively researched and used, particularly in the vocoder of radio communication equipment like HF or VHF equipment. Implementing security solutions for these devices are challenging due to the crucial role played by the vocoder in signal processing prior to encryption. The paper first analyzes the two algorithms LPC and MELP and implements them on the current popular hardware technologies ARM and DSP to give an evaluation direction when choosing technology to serve the design of vocoders. There are many different methods of speech quality assessment in this paper, the PESQ method according to the ITU-T P862 standard was used to evaluate the results of the implementation of the proposed algorithms. The results show that the quality of the compression rate reduction of about 2 kbps is still satisfactory, and dedicated DSP technology for better speech quality results is a basis for helping vocoder device developers choose the right hardware technology when designing products.