Explain the modulation techniques used in Bluetooth technology. Blue tooth uses Frequency Hopping Spread Spectrum technique which is used in spread spectrum signal transmission. During radio transmission, frequencies are switched repeatedly, to help reducing unlawful access to cross paths which causes interruptions. FHSS makes Bluetooth communication more robust and secure. The speed of interferences from other devices will be reduced, though it will not cause the transmission to stop.
Adaptive modulation and coding methods, OFDM, GMSK, QAM, CDMA, DMT and similar methods are utilized in the areas of wireless, cellular and satellite communication systems. These modulations are used in wireless, cellular, wired line and satellite communication systems.
New technologies such as MIMO, BLAST and space-time coding are used in transmission data communication systems.