DSSS: Advantages and Disadvantages

This page covers the advantages and disadvantages of Direct Sequence Spread Spectrum (DSSS). It also provides a basic introduction to DSSS.

What is DSSS?

• DSSS stands for Direct Sequence Spread Spectrum.
• In this technique, information bits are modulated using PN (Pseudonoise) codes generated by a PRS (Pseudonoise Random Sequence) generator.
• The PN code has a shorter duration compared to the information bits, resulting in the modulated spectrum occupying a larger bandwidth.
• Information bits are spread across both the time and frequency domains.
• DSSS can deliver a capacity of approximately 11 Mbps.
• It is a very sensitive technology.
• It is typically used in point-to-point scenarios.

Figure 1 depicts DSSS transmitter and DSSS receiver block diagrams.

Benefits or Advantages of DSSS

The following are the benefits or advantages of DSSS:

• By using both time and frequency planes for the transmission of information bits, the effects of interference and fading can be minimized to a great extent.
• It can be employed in point-to-point applications at a rate of 11 Mbps.
• It supports a higher coverage range due to the low SNR (Signal-to-Noise Ratio) requirement at the receiver.

Drawbacks or Disadvantages of DSSS

The following are the disadvantages of DSSS:

• It is a very sensitive technology in harsh environments, such as collocated cells, larger coverage areas, multipath scenarios, and in the presence of frequencies used for Bluetooth networks. This sensitivity arises because it operates at a narrow bandwidth.
• The system is more prone to errors at lower levels compared to FHSS (Frequency-Hopping Spread Spectrum).