Time Hopping Spread Spectrum

Essay by hilmer93University, Bachelor'sB+, October 2013

download word file, 5 pages 0.0

Table of Content

Introduction 1-2

Concept and features of THSS 3-4

Why was it developed? 5

Advantages and Disadvantages 6

How does it work? 7-8

Use, Importance and Application 9

Conclusion 10

Reference 11


Spread spectrum technology was invented in the 1940s, and has been used extensively since then for military and other applications. Spread spectrum is a technique used in radio transmissions whereby a transmitted signal is spread over or occupies a wide frequency band. In the case of radio transmission, the signal spreads over a much larger part of the Radio Frequency spectrum that is much wider than the minimum bandwidth required for transmitting the information being sent. This makes the signal more robust against interference and jamming. During the process of this technique the narrowband signal is manipulated (scrambled) prior to transmission. The manipulation requires a pseudo random noise. Pseudo random noise is similar to noise and although it seems to lack any definite pattern, pseudo random noise consists of a deterministic sequence of pulses that will repeat itself after its period.

Pseudo random noise code is basically a method of transmitting messages in the presence of interference or noise. Spread spectrum communications cannot be said to be an efficient means of utilizing bandwidth. However, it does come into its own when combined with existing systems occupying the frequency.

There are three types of spread spectrum methods:

Frequency hopping spread spectrum

Direct sequence spread spectrum

Time hopping spread spectrum

When it comes to the case of the time hopping system, in this method a sequence of short duration pulses is transmitted which is generated from the narrowband information that carries signal through scrambling or manipulating with a pseudo random modulated impulse train. The short pulse duration generates the spread spectrum profile. Time Hopping is used as...