Abstract: A modem includes a base unit for transmitting a data signal, and a communication card which receives the data signal from the base unit over a wireless medium and which performs echo canceling on the data signal. The base unit is in communication with a telephone line and receives an original signal from the telephone line. The base unit generates an RF modulated signal based on the original signal. The base unit includes a transmitter for transmitting the data signal. Circuitry in the base unit receives the original signal from the telephone line and generates a combined data signal from the original signal and echo signals and maintains a peak voltage of the combined signal which is within the linear amplification region of the transmitter.

Abstract: Circuitry to transmit an analog data signal over a wireless communication link includes a receiver that receives a data signal, an automatic gain control circuit that keeps a peak amplitude of the data signal substantially constant and within a predetermined linear amplification range, and a transmitter, having the predetermined linear amplification range, that receives the data signal from the automatic gain control circuit and that outputs the data signal.

Abstract: A modem transmits data between a computer and a telephone line. The modem features a base unit which receives a data signal from the telephone line and which transmits the data signal over a wireless link. A device receives the data signal over the wireless link and outputs an analog data signal that corresponds to the data signal. A modem card receives the analog data signal from the device, digitizes the analog data signal to produce a digital signal, demodulates the digital signal, and provides an output digital data signal to the computer.