Wireless modem
First Claim
1. An apparatus comprising:
- a base unit for coupling to a telephone line; and
a remote unit for communicating with the base unit over a wireless medium;
wherein the base unit includes a transmitter for direct analog modulation of an original analog voiceband data signal received over the telephone line and transmitting the modulated signal over the wireless medium, and level control circuitry coupled to the transmitter that controls a level of the original analog voiceband data signal to be substantially in a linear range of the transmitter;
wherein the remote unit includes a receiver for receiving the modulated signal over the wireless medium and direct analog demodulation of the original analog voiceband signal, and an interface to a modem circuit for decoding a data stream encoded in the original analog voiceband signal;
wherein the level control circuitry that controls a level of the signal comprises an automatic gain control circuit that controls a peak level of the signal; and
wherein the automatic gain control circuit uses a dial tone of a telephone connection or a DC current of a telephone loop to set a gain level for the original signal at a beginning of communication, the gain level remaining substantially constant during communication.
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Accused Products
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.
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Citations
8 Claims
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1. An apparatus comprising:
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a base unit for coupling to a telephone line; and a remote unit for communicating with the base unit over a wireless medium; wherein the base unit includes a transmitter for direct analog modulation of an original analog voiceband data signal received over the telephone line and transmitting the modulated signal over the wireless medium, and level control circuitry coupled to the transmitter that controls a level of the original analog voiceband data signal to be substantially in a linear range of the transmitter; wherein the remote unit includes a receiver for receiving the modulated signal over the wireless medium and direct analog demodulation of the original analog voiceband signal, and an interface to a modem circuit for decoding a data stream encoded in the original analog voiceband signal; wherein the level control circuitry that controls a level of the signal comprises an automatic gain control circuit that controls a peak level of the signal; and wherein the automatic gain control circuit uses a dial tone of a telephone connection or a DC current of a telephone loop to set a gain level for the original signal at a beginning of communication, the gain level remaining substantially constant during communication. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification