Noise reduction and echo cancellation system

The paper presents an algorithm, based on the transform domain approach, used in order to reduce noise and to eliminate echo in telecommunications systems such as hands free telephony. The algorithm has the ability to suppress the noise from the microphone signal as well as the acoustic echo. The audio echo cancellation is based on transform domain LMS adaptive filter theory. A noise reduction filter is introduced in order to achieve better performance. The computational complexity is increased, but the system can be implemented in real time using a DSP microcomputer.