An adaptive frequency hopping apparatus in wireless personal area network system

摘要

PURPOSE: An adaptive frequency hopping device for a WPAN(Wireless Personal Area Network) system is provided to accurately transmit a certain data packet by previously predicting estimating a channel state of an operation band and transmitting the packet to a suitable band. CONSTITUTION: A frequency table(10) monitors each channel state, and stores and outputs information about each accumulated channel state. A frequency hopping generator(11) generates and outputs a frequency pattern according to a predetermined rule. A link controller(12) generates an ACL(Asynchronous Connection Less) according to the output signals of the frequency table(10) and the frequency hopping generator(11), and controls the selection of a channel avoidance mode and a channel selection mode. A packet processor(13) synthesizes an inputted SCO(Synchronous Connection Oriented) and the ACL, and generates packet data. A GFSK(Gaussian Frequency Shift Keying) modulator(14) performs a GFSK modulation of the output signal of the packet processor(13). A mode selector(15) selects the channel avoidance mode and the channel selection mode according to the output signals of the frequency hopping generator(11) and the link controller(12). A frequency synthesizer(16) synthesizes frequencies according to the output signal of the mode selector(15). The first multiplier(17) mixes the output signals of the frequency synthesizer(16) and the GFSK modulator(14), and outputs the mixed signal as a transmission signal. The second multiplier(18) multiplies the output signal of the frequency synthesizer(16) by a receiving signal, and modulates the multiplied signal. An RSSI(Received Signal Strength Indicator) detector(19) detects an RSSI from the output signal of the second multiplier(18). A GFSK demodulator(20) performs a GFSK demodulation of the output signal of the second multiplier(18). A packet processor(21) recovers data with a packet type from the output signal of the GFSK demodulator(20). A channel detector(22) predicts a channel state using the output signals of the RSSI detector(19) and the packet processor(21), and stores the estimated value in the frequency table(10).