Delta modulation is a conversion technique of signals. You do it from analog to digital or vice versa. Delta modulation helps in the transmission of digital data over wireless networks.
Delta modulation is a modulation technique that helps to send digital data over a radio frequency signal.
Delta modulation is a system of encoding and decoding that transmits communications. This is all while consuming minimal bandwidth and generating minimal interference to surrounding codes or signals.
This type of modulation has many benefits. They are the ability to encode and decode analog signals. All happens without distortion and utilizing very little bandwidth. It is also more immune to interference than other modulation techniques.
This technique is also known as dual-time domain modulation. This technique is helpful in digital satellite transmission. It has also been used for high-speed video transmission. This is on satellite, cable television, over IP-based networks. It also provides a data signal for direct broadcast TV.
The basic idea is that it can be in any analog waveform. This is if its spectrum has at least one discernible peak or valley—the ideal waveform would then have a single characteristic shape or ‘skew’.
Working Principle of Delta Modulation
Delta Modulation can help to send any digital data over any FM signal. It does this without suffering from the usual problems. Such problems are FM interference, noise, multipath fading, and so on.
This is because the digital data can perform as an extra modulation sideband. It does not generate any problems with FM. The sideband energy is lower than the carrier (FM) energy.
The working theory of DM is a distinction between the current and earlier recorded data performance. The discrepancy determines whether the conveyed values go up or down.
The encoding and decoding of the data then involve taking an average of the current sample value and the last recorded value. The basic idea is that the difference between the two numbers/symbols represents a phase change.
Applications of Delta Modulation
Practical Application
The delta modulation helps in cellular radio systems. This helps to send and receive short digital messages on a radio channel. This technology enables two-way communication between mobile terminals and base stations.
Before this technology, the transmission was a one-way mode between the stations. It means that only the transmitting station can send a message.
This method proved to be difficult for large area coverage. This is because when any user informs the receiving station about his location he has to carry out a search procedure.
That process is not very effective as this method takes time and consumes a lot of bandwidth. But with constant improvements, coverage can complete using the delta modulation technique.
Packet Modem – Delta Modulation
Delta modulation works in the packet modems of the broadband internet service providers to send data. Delta modulation works for the transmission of data.
This process is pulse modulation. It involves the conversion of analog data into a continuous series of pulses or dots and dashes of varying widths.
The microprocessor controls the conversion, which helps with some help from software. The data are then sent to the digital modem where they pass through a standard telephone line to the Internet.
Advantages and disadvantages of delta modulation
Advantages
⦁ This technique can help in all places where radio communication is essential. The distance across which the signal works is also very wide. It covers a total distance of 80 km, in the case of wireless data transmission.
⦁ It will not face the usual problems of FM interference, noise, multipath fading, and so on. This is because the digital data can carry it as an extra modulation sideband. It does not generate any problems with FM and CDMA signals. The sideband energy is lower than the carrier (FM) energy.
⦁ The working theory of delta modulation is a distinction between the current and earlier recorded data stored. The discrepancy determines whether the conveyed values are going up or down.
⦁ The encoding and decoding of the data then involve taking an average of the current sample value and the last recorded value. The basic idea is that the difference between these two numbers/symbols represents a phase change.
⦁ The biggest advantage is that it avoids any phase change. As a result, it will not distort original digital data. This ensures that any other information, which uses delta modulation is completely distortion-free. It also saves more time in comparison to other carriers for increasing transmission distance and quality etc.
Disadvantages
⦁ Idle Noise: Idle noise is another problem with Delta modulation. Idle noise is the random and uncorrelated signal which gets generated from the radio channel. It produces cross talk as it gets induced onto the intended signal by antenna, receiver, transmitter, duplexer, etc.
⦁ High bit rate: When the bit rate is high, the modulation amplitude must be of a lower value. If it is higher then it will affect the amplitude of the symbol, thereby degrading its quality.
⦁ Long duration: It can be a problem with heavy ionospheric conditions or meteor trails and so on. When we use this modulation for a long duration, then there are chances of error transmission. This is because of the low power level at the transmitter and receiver.
⦁ Limited Practical Usage: The primary reason for this is its dependency on the carrier. It is not possible to make use of signals of lower carrier frequency because they cannot distinguish them from their signals.