Method and apparatus for improving classroom amplification systems and other rf-type amplification systems

Abstract

An RF-type amplification system, such as a classroom amplification system, employs technology adapted from a cordless telephone system to overcome interference. The amplification system includes a portable remote unit ( ) and a base unit ( ). Remote unit ( ) includes: a microphone ( ) for detecting a voice and generating corresponding voice signals; a transmitter ( ) which generates RF signals containing the voice signals as well as control signals provided by the central processing unit ( ) of remote unit ( ), and an antenna ( ) for transmitting the RF signals and for receiving RF signals from base unit ( ). Base unit ( ) includes an antenna ( ) which receives the RF signals transmitted by the remote unit and a receiver ( ) which detects the RF signals and separates the RF signals into the voice signals and control signals. The control signals are identified by a code detector ( ) of base unit ( ) and evaluated by a CPU ( ). If the values of the control signals are as expected, the voice signals are processed through a speech network ( ) and provided at a communications interface to an audio power amplifier ( ) which amplifies the voice signals and supplies the voice signals to speakers which audibly project the voice signals as sound. Base unit ( ) further includes a transmitter ( ) for generating RF signals containing control signals, but no voice signals, that are transmitted to remote unit ( ), thereby effecting one-way transmission of voice signals and two-way transmission of control signals between remote unit ( ) and base unit ( ).