Table of Contents
Which transform is used in SSB SC and why?
Summary. This chapter reviews generation of analytic signals and single-side band (SSB) modulation signals using the Hilbert transform. The system that performs the Hilbert transform (called a Hilbert transformer) is a linear system with a frequency transfer function.
What is single side band used for?
Single sideband, SSB, modulation is used in many voice applications. It is used for HF communications, but forms have been used for analogue TV broadcasting. Single sideband modulation is widely used in the HF portion, or short wave portion of the radio spectrum for two way radio communication.
What does Hilbert transform do?
The Hilbert transform is a technique used to obtain the minimum-phase response from a spectral analysis. When performing a conventional FFT, any signal energy occurring after time t = 0 will produce a linear delay component in the phase of the FFT.
How a SSB & VSB signal can be modulated and demodulated?
Both SSB and VSB can be demodulated using the coherent demodulator shown in Fig. 2a. Both modulation schemes may also be demodulated by reinserting a carrier component and passing the sum through an envelope detector. VSB is used for transmitting the video signal in commercial television broadcasting.
What is SSB system?
In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude modulation, it uses transmitter power and bandwidth more efficiently.
What is SSB and Dsbsc?
DSB-SC stands for Double SideBand Suppressed Carrier and SSB-SC stands for Single SideBand Suppressed Carrier. Both of these are modulation techiques used in AM(Amplitude Modulated) frequency spectrum. The DSBSC modulator process is mentioned in the equations below.
What is SSB generation?
To generate an SSB signal with this method, two versions of the original signal are generated, mutually 90° out of phase for any single frequency within the operating bandwidth. Each one of these signals then modulates carrier waves (of one frequency) that are also 90° out of phase with each other.
What is Hilbert transform in signals and systems?
Hilbert transform of a signal x(t) is defined as the transform in which phase angle of all components of the signal is shifted by ±90o. x(t), ˆx(t) is called a Hilbert transform pair.
How is the Hilbert transform used in communications?
The Hilbert transform uses the phase shifts between the signals to achieve the desired separation, where the phase angles of all components of a given signal are shifted by ±90°, the resulting function of time is known as the Hilbert transform of the signal.
What is single sideband (SSB) modulation?
Single Sideband (SSB) Modulation is an efficient form of Amplitude Modulation (AM) that uses half the bandwidth used by AM. This technique is most popular in applications such as telephony, HAM radio, and HF communications, i.e., voice-based communications.
What is the discrete Hilbert transform?
The discrete Hilbert Transform is a process by which a signal’s negative frequencies are phase-advanced by 90 degrees and the positive frequencies are phase-delayed by 90 degrees. Shifting the results of the Hilbert Transform (+ j) and adding it to the original signal creates a complex signal as we’ll see below.
What is am (double sideband)?
A simple form of AM is the Double Sideband (DSB) Modulation, which typically consists of two frequency-shifted copies of a modulated signal on either side of a carrier frequency. More precisely this is referred to as a DSB Suppressed Carrier, and is defined as
How does a spectral shifter work?
The Spectral Shifter shifts (translates) the spectral content of a signal by modulating the analytic signal formed from the signal whose spectrum we want to shift. This concept can be used for SSB modulation as shown later.