Delta modulation

Delta Modulation

Delta Modulation waveform

Delta modulation is a digital modulation technique used for transmitting analog signals over a digital communication system. It is a form of pulse code modulation (PCM) that uses a one-bit quantizer to encode the difference between the current and previous sample of the analog signal. This article provides an overview of delta modulation, its working principle, advantages, and applications.

Working Principle

Delta modulation works by approximating the analog signal with a staircase waveform. At each sampling interval, the difference between the current and previous sample is quantized into a single bit. If the difference is positive, a binary 1 is transmitted; otherwise, a binary 0 is transmitted. This binary sequence is then decoded at the receiver to reconstruct the analog signal.

The quantization step size, also known as the delta, determines the resolution of the approximation. A smaller delta provides a higher resolution but requires more bits to represent the signal accurately. On the other hand, a larger delta reduces the number of bits required but results in a lower resolution.

Advantages of Delta Modulation

Delta modulation offers several advantages over other modulation techniques:

1. Simplicity: Delta modulation is a relatively simple modulation technique, requiring only a one-bit quantizer and a simple decoder at the receiver.

2. Low bandwidth requirement: Due to its one-bit nature, delta modulation requires a lower bandwidth compared to other PCM techniques, making it suitable for low-bandwidth communication systems.

3. Robustness: Delta modulation is less sensitive to channel noise and distortion compared to other modulation techniques. This makes it suitable for transmission over noisy channels.

Applications

Delta modulation finds applications in various fields, including:

1. Voice communication: Delta modulation is commonly used in voice communication systems, such as mobile phones and voice over IP (VoIP) applications. Its low bandwidth requirement and robustness make it suitable for transmitting voice signals.

2. Data transmission: Delta modulation can be used for transmitting data over low-bandwidth channels, where the accuracy of the transmitted data is not critical.

3. Control systems: Delta modulation is also used in control systems, where it can be used to transmit control signals with low bandwidth requirements.

See Also

• Pulse Code Modulation
• Digital Communication
• Analog-to-Digital Conversion