Bluetooth uses which spread spectrum technology?

Bluetooth uses which spread spectrum technology?

• A. Direct-sequence spread spectrum (DSSS)
• B. OFDM
• C. Frequency-hopping spread spectrum (FHSS)
• D. CDMA

Answer: (C)

Bluetooth uses a frequency-hopping spread spectrum approach. It continuously switches its carrier across many 1-MHz channels in the 2.4 GHz band according to a pseudo-random sequence shared by the devices. This rapid hopping reduces the impact of interference and lets multiple Bluetooth connections share the same airwaves without staying on one frequency long enough for a single interference event to cause lasting problems. Direct-sequence spread spectrum would spread data across the band with a spreading code, which Bluetooth does not use. OFDM is a multi-carrier modulation used by Wi‑Fi and others, not Bluetooth’s basic scheme. CDMA relies on codes for access rather than frequency hopping. So the spread-spectrum method Bluetooth employs is frequency hopping.

Bluetooth uses a frequency-hopping spread spectrum approach. It continuously switches its carrier across many 1-MHz channels in the 2.4 GHz band according to a pseudo-random sequence shared by the devices. This rapid hopping reduces the impact of interference and lets multiple Bluetooth connections share the same airwaves without staying on one frequency long enough for a single interference event to cause lasting problems. Direct-sequence spread spectrum would spread data across the band with a spreading code, which Bluetooth does not use. OFDM is a multi-carrier modulation used by Wi‑Fi and others, not Bluetooth’s basic scheme. CDMA relies on codes for access rather than frequency hopping. So the spread-spectrum method Bluetooth employs is frequency hopping.