Standard AM already has double sideband. When you talk about double sideband, however, often the meaning is usually "double sideband, suppressed carrier". By suppressing the carrier, you can impute more power into the sidebands, because you are not providing power to the carrier, which accounts for a significant percentage of the total power. Since the sidebands actually contain the signal, you can boost the signal to noise ratio by suppressing the carrier. This comes at a cost, however, in complexity, because you need to regenerate the carrier in order to demodulate the signal.
In fact, many systems use single sideband, suppressed carrier, doubling the available power to the sideband containing the signal over double sideband suppressed carrier. This works, again at the cost of receiver and transmitter complexity, because the two sidebands contain the same information.
Single Sideband is effectively the same as standard AM, except that the carrier and one of the two sidebands is suppressed. This allows you to put more power into the information carrying part of the signal, at the complexity of having additional circuitry on both ends to modulate and demodulate.
Double-sideband modulation is a type of amplitude modulation where both upper and lower sidebands are present with the carrier signal. The dynamic characteristic of double-sideband modulation is that it allows for efficient use of bandwidth but is susceptible to fading and interference.
Standard AM sideband refers to the amplitude modulation (AM) technique where a carrier wave is modulated by an audio signal, producing two sidebands: the upper sideband (USB) and the lower sideband (LSB). In traditional AM broadcasting, both sidebands and the carrier are transmitted, resulting in a wider bandwidth and potentially more power usage. However, sideband modulation techniques like single sideband (SSB) can transmit only one of the sidebands and the carrier can be suppressed, allowing for more efficient use of bandwidth and power. Standard AM is commonly used in AM radio broadcasting.
Upper sideband = Carrier frequency + modulating frequencyLower sideband = Carrier frequency - modulating frequency
With full double sideband AM the bandwidth of the modulated signal is twice that of the baseband information signal. With suppressed carrier single sideband AM the bandwidth of the modulated signal is identical to that of the baseband information signal. With vestigial sideband AM the bandwidth of the modulated signal is somewhere between the above two cases, depending on how much of the vestigial sideband is included.
Explain the difference between the various forms of a.m & f.m and which jutifies the radio station's choice of modulation for each waveband?
Analog modulationIn analog modulation, the modulation is applied continuously in response to the analog information signal.Common analog modulation techniques are:Amplitude modulation (AM) (here the amplitude of the modulated signal is varied) Double-sideband modulation (DSB) Double-sideband modulation with unsuppressed carrier (DSB-WC) (used on the AM radio broadcasting band)Double-sideband suppressed-carrier transmission (DSB-SC)Double-sideband reduced carrier transmission (DSB-RC)Single-sideband modulation (SSB, or SSB-AM), SSB with carrier (SSB-WC)SSB suppressed carrier modulation (SSB-SC)Vestigial sideband modulation (VSB, or VSB-AM)Quadrature amplitude modulation (QAM)Angle modulation Frequency modulation (FM) (here the frequency of the modulated signal is varied)Phase modulation (PM) (here the phase shift of the modulated signal is varied)
Shasta sideband was created in 1933.
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single sideband full carrier
If you subtract from the carrier frequency the frequency of the tone that modulates it, then filter out the carrier frequency, then you have a lower sideband frequency. If you add to the carrier frequency, filter out the carrier, then you have an upper sideband frequency.
In regards to the radio transmission mode, SSB is an improvement of AM, and there are generally three ways single sideband can be generated -- filtering out the unwanted sideband and suppressing the carrier; using phasing to suppress the unwanted sideband and carrier (Hartley modulator); or quadrature mixing and filtering (Weaver modulator).