A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

At least one tone is generated. An output signal is generated in response to an input signal and the at least one tone. The output signal is modulated. The input signal and the at least one tone are represented in the modulated output signal. The at least one tone is outside a bandwidth of the input signal as represented in the modulated output signal. The modulated output signal is amplified. The at least one tone in the amplified signal is attenuated after the amplifying.

Aspects of the present disclosure aim at providing three pseudo-orthogonal waveforms that can be used for transmitting 3n bits (n bits over each waveform) at a given frequency. Use of such three pseudo-orthogonal waveforms can be used in applications such as QAM to create a 3-dimensional QAM, along with use in other like applications such as in Orthogonal frequency-division multiplexing (OFDM), Quadrature Phase Shift Keying (QPSK), Binary Phase Shift Keying (BPSK), among others. The three pseudo-orthogonal waveforms can in general be used in any application where complex number algebra is used, and can help increase transmission capacity by additional 50%.

A digital signal up-converting apparatus includes: a clock generating circuit arranged to generate a reference clock signal; an adjusting circuit coupled to the clock generating circuit and arranged to generate a first clock signal and a second clock signal according to the reference clock signal; a baseband circuit coupled to the adjusting circuit for receiving the first clock signal, wherein the baseband circuit further generates a digital output signal according to the first clock signal; and a sampling circuit coupled to the adjusting circuit and the baseband circuit for receiving the second clock signal and the digital output signal, wherein the second clock signal and the digital output signal are non-overlapping; wherein the sampling circuit samples the digital output signal based on the second clock signal and then combines the sampled digital output signal in order to generate a combined digital signal.

A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

An optimization unit in an optical receiver divides a symbol region out of a plurality of symbol regions into which signal points that specifies symbol information included in an optical signal are classified, into a plurality of division regions from the symbol center coordinate of the symbol region. Moreover, the optimization unit accumulates the signal points of the symbol information for every division region in the symbol region. Furthermore, based on the accumulated number of signal points for every division region, the optimization unit controls the average length of a phase estimation unit when the phase noise of the optical signal is calculated.

This application relates to the field of wireless communication, and in particular, to a multi-channel hybrid transmission technology. In an embodiment, a data transmission method comprises: generating, by a first wireless communications device, a physical protocol data unit (PPDU), wherein the PPDU comprises a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), and two signature symbols after the L-SIG in a time-domain, and wherein the two signature symbols are identical and are modulated based on binary phase shift keying (BPSK), the two signature symbols identify a wireless communications standard the PPDU complies with; and transmitting, by the first wireless communications device, the PPDU to a second wireless communications device.

This application relates to the field of wireless communication, and in particular, to a multi-channel hybrid transmission technology. In an embodiment, a data transmission method comprises: generating, by a first wireless communications device, a physical protocol data unit (PPDU), wherein the PPDU comprises a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), and two signature symbols after the L-SIG in a time-domain, and wherein the two signature symbols are identical and are modulated based on binary phase shift keying (BPSK), the two signature symbols identify a wireless communications standard the PPDU complies with; and transmitting, by the first wireless communications device, the PPDU to a second wireless communications device.

A signal processing device that performs time frequency analysis on a signal includes: a phase multiplication unit to perform a plurality of phase multiplications on a received signal; and a signal addition unit to add signals obtained by the plurality of phase multiplications depending on a synthesis zone obtained by synthesizing a time zone related to the time frequency analysis to be executed with respect to the signal.