443 results about "Signal envelope" patented technology

A radio frequency amplification stage including an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, including a circuit for providing a reference signal representing the envelope of the input signal; a circuit for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and a circuit for generating an adjusted selected power supply voltage, including an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage.

A transceiver comprises an amplifying circuit for amplifying an input signal to produce an output signal. A power supply is operable for varying the level of power supplied to the amplifying circuit in response to variation of an input signal envelope directed to the power supply. A processing circuit is operable for digitally detecting the input signal envelope to provide variation of the power supply level. The processing circuit is further operable for digitally delaying the digital input signal envelope to time align the power supply level with the input signal.

The invention relates to the offset-modulation orthogonal frequency division multiplexing and multicast communication with a cyclic prefix, which comprises a transmitted signal producing method at the transmitting end and a received signal processing method at the receiving end. The method comprises the following steps of: carrying out the generalized discrete Fourier transform on real value digital baseband modulation signs at the transmitting end to obtain frequency-domain signals; carrying out the conjugate symmetrical expansion, the frequency-domain filtering and the sub-carrier mapping on the frequency-domain signals; carrying out the inverse fast Fourier transform on the frequency-domain signals obtained after the sub-carrier mapping; inserting the cyclic prefix to obtain time-domain transmitted signals; removing the cyclic prefix at the receiving end; carrying out the fast Fourier transform on the signals with the cyclic prefix removed to obtain frequency-domain received signals; and carrying out the iterative detection decoding based on the multi-user combined frequency-domain balance on the frequency-domain received signals. The invention obtains the low signal envelope fluctuation performance under the condition of maintaining the frequency spectrum efficiency, and the transmission reliability is ensured in lower complexity by the iterative received signal processing method based on the multi-user combined frequency-domain balance.