Abstract: A clock circuit for generating a clock signal includes a first clock generator configured to generate a first clock signal, a second clock generator configured to generate a second clock signal, and a selector connected to the first clock generator and the second clock generator. The selector is configured to select one of the first and second clock signals as a selected clock signal based on a selection signal. The selector is configured to transmit, if a selection of the selector changes from the second clock signal to the first clock signal, a turn-on request signal to at least one first component to enable the at least one first component. The at least one first component is configured to send a turn-on acknowledgement signal to the selector in response to the turn-on request signal. The first clock generator includes the at least one first component.

Abstract: A clock circuit for generating a clock signal includes a first clock generator configured to generate a first clock signal, a second clock generator configured to generate a second clock signal, and a selector connected to the first clock generator and the second clock generator. The selector is configured to select one of the first and second clock signals as a selected clock signal based on a selection signal. The selector is configured to transmit, if a selection of the selector changes from the second clock signal to the first clock signal, a turn-on request signal to at least one first component to enable the at least one first component. The at least one first component is configured to send a turn-on acknowledgement signal to the selector in response to the turn-on request signal. The first clock generator includes the at least one first component.

Abstract: Method for providing frequency-hopping OFDMA using symbols of comb patter, the method including the steps of: a) assigning frequency domain signal X(k) of comb pattern (comb symbol, k is frequency index) to modulated data sequence, the comb symbol comprising predetermined number of sub carriers (sub carrier group) which are placed with predetermined interval in the whole available frequency band; b) getting the comb symbol hopped for the comb symbol to have independent frequency offset; and c) inverse fast fourier transforming the comb symbol to time domain signal x(n) (n is time index) and transmitting the signal.

Abstract: Method for providing frequency-hopping OFDMA using symbols of comb patter, the method including the steps of: a) assigning frequency domain signal X(k) of comb pattern (comb symbol, k is frequency index) to modulated data sequence, the comb symbol comprising predetermined number of sub carriers (sub carrier group) which are placed with predetermined interval in the whole available frequency band; b) getting the comb symbol hopped for the comb symbol to have independent frequency offset; and c) inverse fast fourier transforming the comb symbol to time domain signal x(n) (n is time index) and transmitting the signal.