What is synchronization in spread spectrum?
4.1 SYNCHRONIZATION The process of synchronizing the locally generated spreading signal with the received spread-spectrum signal is usually accomplished in two steps. The first step, called acquisition, consists of bringing the two spreading signals into coarse alignment with one another.
What are the modulation schemes of spread spectrum system?
Different types of modulation are used before the DSSS technique is applied. Most common are BPSK and QPSK modulation. The baseband direct sequence spread spectrum system spreads the baseband digital signal using the wide-bandwidth spreading-code signal.
What are the two types of spread spectrum?
There are four generic types of spread spectrum signals:
- Direct Sequence (DS) – The carrier of a DS source stays at a fixed frequency. Narrowband information is spread out into a much larger bandwidth using a pseudo-random chip sequence.
- Pseudo noise (PN)
- Frequency Hopping (FHA)
- Linear Frequency Modulation (chirp)
What is acquisition and tracking?
The operation of GPS signal synchronization is achieved through two steps: acquisition and tracking. Acquisition is a two-dimensional search operation [I] , where the spreading CIA code phase and carrier Doppler shift are coarsely estimated simultaneously.
What will be the correlation of two codes if the two codes are identical?
In general the correlation function has these properties: It equals 1 if the two codes are identical. It equals 0 of the two codes have nothing in common.
What is the importance of spread spectrum?
The main advantage of spread spectrum communication technique is to prevent “interference” whether it is intentional or unintentional. The signals modulated with these techniques are hard to interfere and cannot be jammed. An intruder with no official access is never allowed to crack them.
What are the benefits of spread spectrum system?
Anti-jamming properties: The spread spectrum technique widens the bandwidth of the signal until it equals the original bandwidth plus the bandwidth of the pseudo-random noise injected. The pseudo-random noise added to the spread spectrum technique prevents jamming and interference in wireless systems.
Which of the following is the main characteristics of spread spectrum?
Explanation: Spread spectrum techniques employ a transmission bandwidth that is several orders of magnitude greater than the minimum required signal bandwidth. On the other hand, primary objective of all the modulation schemes is to minimize the required transmission bandwidth.
What are the applications of spread spectrum?
Current applications of spread spectrum technology include wireless LANs (local area networks), bar code scanners, and microphones. This technology improves the efficiency and effectiveness of business processes, many of which are finding that wireless communications are requisite for success.