The Advantages of Delta Modulation

By Saifuddin Abdullah

The delta analog-to-digital modulation technique is widely used in voice transmission applications such as telephone and radio communications, which use the principles of modulation to transmit voice signal frequencies over carrier signals. Delta modulation is specifically applied where timely data delivery at the receiver’s end is more important than data quality. It enjoys particular advantages over other analog-to-digital modulation techniques, including lower noise -- or disruption -- in transmitted data, lower bandwidth consumption, cost-effective operations and data delivery acknowledgment.

High SNR Benefit

Delta modulation offers higher signal-to-noise ratio than other conventional modulation techniques. SNR is the strength ratio between data and noise within a transmitted signal, and is calculated in the units of decibels. In data communications, signal power is always inversely proportional to noise power, which means that higher signal power results in higher SNR. Other common modulation techniques such as pulse code modulation and differential pulse code modulation have lower SNR compared to delta modulation.

Lower Bandwidth Consumption

Delta modulation offers a significant benefit of lower channel bandwidth consumption. The bandwidth of a channel is the range of frequencies allowed for a signal to transmit data. This feature is crucial in data communications, because increasing bandwidth directly hikes the cost and management of a transmission network. Delta modulation provides the benefit of lower bandwidth consumption, which makes the process of data communications more cost effective.

Cost Effective Systems

The cost effectiveness of delta modulation is down to the transmission technique, which employs sending one binary bit as a carrier pulse with one sample of digitized data. This technique lowers the bandwidth of the transmission channel, which eases the burden on the network engineers, managers and architects who design and implement the modulation system.

Feedback Mechanism

Unlike PCM and DPCM, delta modulation gives the additional benefit of data delivery feedback to the transmitters. This indicates that systems designed over delta modulation consider delivery of data bits as the most important task rather than checking for quality and robustness. For this reason, delta modulation is only used in voice communications rather than networks that require quality-intensive images, video and text data.