What is FHSS explain with diagram?
In a frequency-hopping spread spectrum (FHSS) system, the transmitted signal is spread across multiple channels, as shown in Figure 1 below. This baseband signal is then modulated onto a carrier c(t). Figure 1: Block diagram of FHSS transmitter, from William Stallings “Data and Computer Communications”.
What is FHSS and explain its operation?
Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. FHSS is used to avoid interference, to prevent eavesdropping, and to enable code-division multiple access (CDMA) communications.
What is FHSS system?
FHSS is a wireless technology that spreads signals over rapidly changing frequencies. Each available frequency band is divided into subfrequencies, and signals rapidly change, or “hop,” among these subfrequency bands in a pre-determined order.
What are the components of FHSS?
Narrowband.
What type of modulation is used in FHSS?
The modulation technique which is mostly used in FHSS is M-ary FSK and QAM along with convolution coder.
Is Bluetooth a FHSS?
Instead of transmitting over one frequency within the 2.4 GHz band, Bluetooth radios use a fast frequency-hopping spread spectrum (FHSS) technique, allowing only synchronized receivers to access the transmitted data. How is Bluetooth used? Bluetooth can be used to wirelessly synchronize and transfer data among devices.
Do cell phones use FHSS?
The devices that are connected together can include mobile phones, portable computers, personal digital assistants (PDAs), printers, televi- sions and so on. PANs resemble small-scale WLANs. Bluetooth uses FHSS transmission in the same frequency band (2.4 GHz) as microwave ovens and many WLANs.
What is the bandwidth of FHSS?
Frequency-hopping Spread Spectrum (FHSS) Bluetooth, for example, uses the 2.4 – 2.843 Ghz bandwidth, with 79 defined channels.
What is the set of possible carrier frequencies in FHSS?
hopset
24. What is the set of possible carrier frequencies in FH-SS? Explanation: The set of possible carrier frequencies in FH-SS is called hopset. Hopping occurs of a frequency band that includes a number of channels.
What is DSSS and FHSS?
FHSS and DSSS, which stand for Frequency Hopping Spread Spectrum and Direct Sequence Spread Spectrum, are two spread spectrum techniques. The main difference is in how they spread the data into the wider bandwidth. FHSS utilizes frequency hopping while DSSS utilizes pseudo noise to modify the phase of the signal.
How is a DSSS system different from a FHSS system?
• In DSSS, information bits are spread across both frequency and time planes, hence minimizes effect of interference as well as fading. Hence DSSS system prone to errors but at low level compare to FHSS systems. FHSS produces strong bursty errors.
What does FHSS stand for in RF spectrum?
In FHSS, which stands for Frequency Hopping Spread Spectrum, RF carrier frequency is changed according to the Pseudo-random sequence (PRS or PN sequence). This PN sequence is known to both transmitter and Receiver and hence help demodulate/decode the information.
How is data modulated in a FHSS transmitter?
Figure 2 shows the block diagram of a typical FHSS transmitter. First, digital data is modulated using some digital-to-analog scheme. This baseband signal is then modulated onto a carrier c (t). Figure 1: Block diagram of FHSS transmitter, from William Stallings “Data and Computer Communications”.
How is the spreading code determined in FHSS?
Figure 3: The LFSR corresponding to the generator 10011. In the FHSS implementation used in this experiment, the spreading code is determined from the state of the registers as shown in Figure 4. After each time instance, the values in each register “shift” as follows (for the LFSR generated by “10011”):