Difference between FHSS and DSSS

Spread spectrum is a communication technique in which the frequency spectrum of a signal is spread out over a wider bandwidth than the minimum bandwidth required to transmit the information. It is used in wireless communications to transmit signals over a wide frequency range. It involves the spreading of signal energy over a wide range of frequencies, which helps to reduce interference with other signals and improves the reliability of communication. There are two main types of spread spectrum: Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS). 

FHSS (Frequency-Hopping Spread Spectrum)

In FHSS (Frequency-Hopping Spread Spectrum), the frequency of the transmitted signal is rapidly switched in a predetermined pattern. This pattern is nothing but “hopset” which allows the sender and receiver to communicate and reduces interference from other signals or sources. FHSS is a type of multiplexing, which allows multiple signals to be transmitted simultaneously over a shared channel.

Advantages of FHSS

1. FHSS allows multiple signals to share the same frequency band simultaneously.
2. It is more secure than other types of communication.

Disadvantages of FHSS

1. FHSS requires more complex circuitry than other types of communication.
2. It is expensive to implement.

Applications of FHSS

1. Modulates a carrier signal.
2. Used in Wireless Networking Devices like Wi-fi, and Bluetooth.

DSSS (Direct-Sequence Spread Spectrum)

In DSSS (Direct-Sequence Spread Spectrum), the data to be transmitted is first encoded using a “chip code.” The chip code is used to modulate the carrier signal, spreading the transmitted signal across multiple frequency bands. The receiver uses the same chip code to demodulate the received signal, allowing it to recover the original data. DSSS is that it is relatively easy to implement and requires less complex equipment.

Advantages of DSSS

1. DSSS is less likely to be affected by other signals that are transmitted on a single frequency.
2. It has simple circuitry.

Disadvantages of DSSS

1. There is a delay while the signal is processed and spread over a wider bandwidth.
2. The channel bandwidth required is very large.

Applications of DSSS

1. In obtaining message privacy.
2. Code division multiple access with DSSS.
3. To minimize the interference due to multipath propagation.

Differences between FHSS and DSSS

Conclusion

In conclusion, Frequency-hopping spread spectrum (FHSS) and Direct sequence spread spectrum (DSSS) are both types of spread spectrum techniques that are used in a variety of applications, including wireless communication, radar, and GPS. FHSS involves rapid frequency switching of the transmitted signal among a set of specific frequencies, while DSSS involves spreading the spectrum of the original signal over a wider bandwidth by multiplying it with a pseudo-random sequence of bits.