Dsss and correlation

1. What is the difference between FHSS and DSSS?
2. What is the meaning of DSSS?
3. What are the two types of spread spectrum techniques?
4. Why does GPS use DSSS?

What is the difference between FHSS and DSSS?

The DSSS method of modulation has a higher rate of transmission than the FHSS method. The implementation of DSSS at radio frequencies with a high transmission rate costs less than implementing FHSS. At a given transmitting power, FHSS offers higher power spectral density than DSSS.

What is the meaning of DSSS?

Direct-Sequence Spread Spectrum (DSSS) is a transmission technology used in WLAN (wireless LAN) transmissions where a data signal at the sending station is combined with a higher data-rate bit sequence, or chipping code, that divides the user data according to a spreading ratio.

What are the two types of spread spectrum techniques?

There are two predominant techniques to spread the spectrum: 1) Frequency hoping (FH), which makes the narrow band signal jump in random narrow bands within a larger bandwidth. 2) Direct sequence (DS) which introduces rapid phase transition to the data to make it larger in bandwidth.

Why does GPS use DSSS?

DSSS provides the structure for the transmission of ranging signal and essential navigation data such as satellite co-ordinates and health. The ranging signal are pseudo random noise (PRN) codes that binary phase shift key (BPSK) modulate the satellite carrier frequencies.