A bandwidth and energy efficient cooperative diversity scheme based on quadrature signaling is proposed. The quadrature signaling is achieved by transmitting in the in-phase and quadrature components of QPSK modulation. The diversity gain and the bi
Quadrature Amplitude Modulation From Basics to Adaptive Trellis-Coded, Turbo-Equalised and Space-Time Coded OFDM, CDMA and MC-CDMA Systems, 3rd Edition
In wireless communication systems, In-phase and Quadrature (IQ) modulator and demodulator are usually used at transmitter (TX) and receiver (RX), respectively. For Digital-to-Analog Converter (DAC) and Analog-to-Digital Converter (ADC) limited syste
This page explains what quadrature demodulation is and provides insight into the nature
of I/Q signals.
If you have read the previous page, you know what I/Q signals are and how quadrature
(i.e., I/Q-signal-based) modulation is accomplished. In this
We comprehensively characterize the transmission performance of m-ary quadrature amplitude modulation (m-QAM) signals through a silicon microring resonator in the experiment. Using orthogonal frequency-division multiplexing based on offset QAM (OFDM/
We study the performance of automatic bias control for three bias voltages in optical quadrature phase-shift keying modulator. The interaction between multiple bias controls for two Mach-Zehnder modulators' (MZMs') bias voltages and a Mach-Zehnder in
A new two-stage carrier-phase recovery scheme using a combination of an optical pilot-aided algorithm with the crossed constellation transformation algorithm for either square-framed or non-square-framed M-level-quadrature amplitude modulation (QAM)
Light-emitting diode (LED)-based visible light communication (VLC) has become a potential candidate for nextgeneration ultra-high-speed indoor wireless communication. In this paper, four special-shaped 8-quadrature amplitude modulation (QAM) constell
We propose a blind quadrature imbalance (QI) compensation algorithm based on the statistical properties of I and Q signals in a receiver. The algorithm estimates the QI parameters of a receiver by calculating the mean, variance, and correlation coeff
