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DSB-SC is basically an amplitude modulation wave without the carrier, therefore reducing power waste, giving it a 50% efficiency. This is an increase compared to normal AM transmission (DSB) that has a maximum efficiency of 33.333%, since 2/3 of the power is in the carrier which conveys no useful information and both sidebands containing identical copies of the same information.
Demodulation is the process of extracting the original information-bearing signal from a carrier wave. A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated carrier wave. [1] There are many types of modulation, and there are many types of ...
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave.In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal.
IQ modulation and demodulation. LO is the local oscillator - the carrier sine wave being modulated I(t) and Q(t) are the time-series data for the in-phase and quadrature components.
Illustration of the spectrum of AM and SSB signals. The lower side band (LSB) spectrum is inverted compared to the baseband. As an example, a 2 kHz audio baseband signal modulated onto a 5 MHz carrier will produce a frequency of 5.002 MHz if upper side band (USB) is used or 4.998 MHz if LSB is used.
In an ideal communications system, the carrier signal oscillators of the transmitter and receiver would be perfectly matched in frequency and phase, thereby permitting perfect coherent demodulation of the modulated baseband signal. However, transmitters and receivers rarely share the same carrier oscillator.
In digital modulation, minimum-shift keying (MSK) is a type of continuous-phase frequency-shift keying that was developed in the late 1950s by Collins Radio employees Melvin L. Doelz and Earl T. Heald. [1]
DVB-Flexible Serially Concatenated Convolutional Turbo Codes with Near-Shannon bound performance for telemetry applications, CCSDS-131.2-O-1.; Xiang, Xingyu; Valenti, Matthew C (2012-10-17).