Sub-band Coding of Speech Signals using Multirate Signal Processing and comparing the various parameter of different speech signals by corrupting the same speech signal
Lalitha R Naik · 2015
possible quality using the least possible channel capacity. To save bandwidth in telecoms applications and to reduce memory storage requirements. Maintain certain levels of complexity to reduce the processing delay and cost of implementation. This paper presents a very low bit rate Speech coder based on sub-band coding (SBC) is a method where the speech signal is subdivided into several frequency bands and each band is digitally encoded separately. The Audible frequency spectrum 20Hz – 20 KHz is divided in to frequency sub-bands using a bank of finite impulse response (FIR) filter. The output of each filter is then sampled and encoded. At the receiver, the signals are de-multiplexed, decoded and demodulated and then summed to reconstruct the signal. Cut-off frequency at rate 4 KHz and order of the filter is 20. Coding test show that this new sub band speech coding scheme based on multi rate sampling can not only realize the splitting and combining of the speech bands conveniently, but also obtain the high compression ratio coding of speech signal. It provides a flexible variable bit rate speech coding method and suits packet switching network. It allows the switch node to regulate or control the transmission bit rate of speech within a large flexible range actively. The high amplitude noise has been added in to the current speech signal at a particular sample this means corrupting the original speech signal. This paper mainly concentrating the comparison of Correlation values for different clean speech signals and Correlation values for after adding high amplitude noise to the same speech signals. Taking correlation tests prove that its performance is satisfying. I. Introduction RESEARCH, product development, and new applications of speech coding have all advanced dramatically in the past decade. Research into new coding methods and enhancement of existing approaches has proceeded at a fast pace, fuelled by the market demand for improved coders. Digital cellular and satellite telephony, video conferencing, voice messaging, and Internet voice communications are just a few of the prominent everyday applications that are driving the demand. The goal is higher quality speech at a lower transmission bandwidth. The need will continue to grow with the expansion of remote verbal