When this problem occurs, the QPSK
EVM measurement can be used to confirm that the rest of the transmitter is working as expected.
Proper modulation-encoding combinations NO.1 NO.2 NO.3 NO.4 NO.5 NO.6 Modulation Mode BPSK QPSK QPSK QPSK
8QAM 32QAM LDPC Encoding Rate 1/4 1/4 1/2 4/5 4/5 4/5 Normalized Rate 0.0625 0.125 0.25 0.4 0.6 1.0 Table 2.
Application of forward correction (FEC) negatively effects the transmission using 8PSK and QPSK
modulation types resulting in decrease of the transmission quality.
Received signal noise causes variations in the received modulation levels--causing, for example, the phases of the QPSK
signal to be other than the exact 0-, 90-, 180-, or 270-degree values.
We observe the transmission of BPSK and QPSK
signals over [eta]-[mu] fading channel.
(Meas01) is modulation analysis of the QPSK
baseband signal using the waveforms acquired by the scope.
Savory, "Compensation of frequency offset for 16-QAM optical coherent systems using QPSK
partitioning," IEEE Photonics Technology Letters, vol.
Four Nyquist-shaped 25-GBd quadrature phase-shift keying (QPSK
) modulation channels were successfully multiplexed to a 200-Gb/s super-channel.
In , a kind of all-digital phase-locked loop (ADPLL) for QPSK
combining a first-order frequency recovery loop based on feedback control with a second-order phase-locked loop is proposed.
To demonstrate the phase error effect on conventional demodulator, gain error and frequency shift have been removed from the incoming QPSK
signal as in (1) to ease the calculation.
For 3X3 MIMO communication systems, analysis of full-rate linear and space-time block code under a Rayleigh flat-fading environment has been carried out in  by using linear MMSE and ML receivers to minimize the average symbol error rate (SER) for a QPSK