| 摘要 |
In a mobile radio communication system where a base station is connected to a public switched telephone network, a hybrid unit and an echo canceler are provided in the base station. A mobile radiotelephone unit receives a base-to-mobile coded speech signal from the base station on a downlink channel and transmits a mobile-to-base coded speech signal on an uplink channel. In order to avoid the interruption of a base-to-mobile speech signal at the echo canceler which would occur as a result of a delayed, high-amplitude mobile-to-base analog speech signal, the mobile unit compares the energy parameter of the mobile-to-base coded speech signal and the energy parameter of the base-to-mobile coded speech signal, determines the difference therebetween when the former is higher than the latter, and reduces the energy parameter of the mobile-to-base speech signal by an amount corresponding to the difference. |
