What are the advantage of polsu amplitude madulation .
CW or continuous-wave radar cannot determine range due to the lack of a listening period where the radar signal is silent. Pulse radar has a silent listening period (hence the name pulse radar). Therefore it can determine the range of the object causing the return by counting the elapsed time between transmission and receipt of the echo. The above is not quite correct, Continuous Wave Radar and Pulsed Radar differ by there relationship between the Pulse Width (tau) and the scene size (Swath). CW Radar's determine range by Frequency Modulation (FM) ranging this means that they ramp the RF frequency within the pulse during the transmission and are known as FMCW Radar. Pulsed Radar on the other hand use the pulse timing but can also use the FM Ranging trick to enhanced there signal to noise and reduce there probability of interference or detection/interception. CW radar can deduce range by delaying the transmit signal and mixing it with the receive such that it becomes a homodyne receiver and in such cases it is usual to ramp the RF and perhaps use two aerials rather then just one with a duplexer switch like in a Pulse radar system. Edit- hmm i feel the above answer is bit too complex... i don't think typical person would go as far as concerning FM or Pulse Delay Ranging here's my Answer DIFFERENCES BETWEEN PULSE AND CW RADAR Basis -Transmission Pulse RADAR puts delay between transmitting and receiving periods so the time between transmitted pulse and received pulse is different While CW RADAR, Transmit continuously -Antennas Pulse RADAR may use same antenna for Receiving and Transmitting , when transmitting the receiver is "blanked" and while Receiving the receiver is Activated and transmitter is blanked .. this is done by a device called "Duplexer" CW RADAR typically used 2 Antennas, one for transmit another one to Receive since there are no delay to receive as what usually seen in pulse RADAR -Ranging technique Pulse RADAR may use "Pulse Delay Ranging" to provide Range measurements , Frequency Modulation Ranging may also possible , especially for pulse RADAR that transmit many pulses and have very shot time to "listen" example is FMICW (Frequency Modulated Interrupted Continuous Wave RADAR) While CW RADAR provides Range by means of Doppler based Ranging (FM Ranging)
Vestigial SideBand. It is a type of signal modulation (filtering) used in the television communication industry. It is used to help remove signal redundancy in Pulse Amplitude Modulated (PAM) signals. Also look up 8VSB and A-VSB which are variants of VSB.
The leading edge of a radar pulse determines range accuracy. The trailing edge, along with pulse width, determines minimum range.
Yes. It is done by a technique called pulse width modulation. Similar to the principle used by incandescent lamp dimmers. Reduced duty cycle = reduced average current/power = reduced apparent brightness. Integrated circuits for this purpose are available from several sources.Artificial means of dimming LEDs also exist such as the patent-pending LEDdim dots and blocks.
Delta modulation is not a type of quality conversion and runs on digital-to-analog, analog-to-digital. Differential pulse code modulation has a higher quality of conversion and runs on a 1-bit data stream.
what is delta modulation and compare with pcm
There is no difference.
delta modulation refers to the procedure of encoding and thereby transmitting only the difference between consecutive samples instead of sending each of the samples themselves. This method is useful only when the vaiation in the amplitude of the signal is small, otherwise, it leads to a phenomenon called "slope overload".Pulse code modulation is the procedure where each of the levels of an analog signal is assigned a value closest ro a quantizer level used to quantize the signal...Another method of PCM that can be confused with Delta Modulation is the D(ifferential)PCM. Here, the difference between the signals is encoded based on its magnitude..
Analog Pulse modulation is discreet in time but the formation is transmitted in continuous form. In digital pulse modulation, not only the time axis is discreet but the information is also in digital form. Examples of Analog PM are PAM and PTM i.e pulse amplitude and pulse time modulations respectively. Examples of Digital PM are PCM and PDM i.e pulse code and pulse delta modulations respectively.
Frequency modulation, as the name suggests, modulates the carrier by changing the frequency of the signal emitted. Pulse width modulation, changes the on-time of a square wave, but leaves the frequency of the carrier wave unchanged. So, in frequency modulation, the frequency will vary between, say, 80kHz and 120kHz with a constant power level, but in pulse width modulation, the frequency will stay at 100kHz, but the on-time (the length of each pulse) will vary, hence the power level will vary accordingly.
PAM-pulse Amplitude Modulation It encodes information in the amplitude of a sequence of signal pulses. PPM-Pulse Position modulation PWM-Pulse Width Modulation.It results in variation of average waveform.
advantage of pulse position modulation
It is a type of Pulse modulation as in PPM the position of pulse of carrier pulse train is varied in accordance with the modulating signal.
It signals the difference between successive sample sizes
Explain with diagram the technique Pulse-width modulation?
The first step in the Pulse Code Modulation is the Sampling Process!