A Modem is a kind of data communication device, which is a bridge between a computer and a telephone line to transmit data. Typically, computers transmit data through digital signals, while telephone lines support analog signals. Therefore, the function of the modem is to convert the digital signal into analog signal, and then transmit it over the telephone line, and then convert the analog signal into digital signal for the computer to use.
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Specifically, the basic functions of a modem are two:
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1. modulation: The conversion of digital signals into analog signals. In the process of modulation, the modem uses a coding method called modulation scheme to convert the digital signal into a variety of signal waveforms, such as carrier modulation (CM), frequency shift keying (FSK), phase shift keying (PSK) and amplitude keying (ASK).
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2. demodulation: The conversion of analog signals into digital signals. In the process of demodulation, the modem decodes the waveform received from the signal, converting the signal from an analog signal to a digital signal that can be read by the computer.
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The speed of the modem is also a very important feature, and baud (bps) is generally used as a unit to express the rate. In digital communications, the speed of the modem can determine its maximum transmission speed.
Modem: Modem. It is designed for the digital signal of data communication to be transmitted over a long distance on an analog channel with limited bandwidth. It is generally composed of baseband processing, modulation and demodulation, signal amplification and filtering, equalization and so on.
Modulation is the combination of the digital signal and the audio carrier to produce an audio signal (analog signal) suitable for transmission on the telephone line, and demodulation is the recovery of the digital signal from the audio signal.
Modem: Short for modulator and demodulator, a piece of computer hardware [1] that translates a computer's digital signals into analog signals that can be transmitted along ordinary telephone lines, which in turn can be picked up by another modem at the other end of the line and translated into a language that the computer understands. This simple process completes the communication between the two computers.
The modem is composed of two parts: a modulator and a demodulator. The modulator modulates the data information into a signal suitable for transmission channel transmission, while the demodulator demodulates the received signal into data information. The modem belongs to the data circuit equipment DCE in the data communication equipment.
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Modulation is to use baseband pulse to control a certain parameter of the carrier waveform to form a signal suitable for line transmission. Demodulation is to remove the carrier from the analog signal transformed by the modulator to restore the original baseband digital signal when the modulated signal reaches the receiving end. The use of modems can also convert audio signals into higher frequency signals and convert higher frequency signals into audio signals, so another purpose of modulation is to facilitate line multiplexing in order to improve line utilization.
A modem is a device used for digital signal transmission, which is able to convert digital signals into analog signals and convert analog signals into digital signals. It can provide high quality digital signal transmission, and can improve the efficiency of signal transmission.
It can be used for broadband data transmission, such as broadband Internet access, digital television, digital telephony, etc. It can provide high-speed data transmission and can improve the transmission quality of the signal.
It is an electronic control device that transfers digital signals to analog signals, and it is divided into two parts: modulator and demodulator, corresponding to digital signals and analog signals respectively, which is a remote control system