Speech coding for wireless communication
Paul G. Mermelstein · 2002
Personal communication systems will be judged primarily on the quality of speech communication they provide. The voice-call capacity depends directly on the bit-rate required to achieve the quality objectives of the specific service. To provide speech quality on wireless systems that is comparable to that attained on today's wireline systems, at least 16 kb/s are required. New algorithms are being considered for a standard to transmit speech at 8 kb/s in the presence of modest transmission errors. Mobile systems with slightly lower quality requirements in service today employ 8 kb/s (IS-54 and IS-95) and 13 kb/s (GSM), respectively. Efforts are under way to halve these values and thereby double the capacity. The paper reviews current research into achieving higher speech quality at lower bit rates under a variety of environmental and transmission conditions. It provides a short-range perspective on where significant progress is expected in the short-term.>