Analysis shows that 400 GbE links using DSP-enabled 5×80Gb/s PAM-4, 4×100Gb/s hybrid CAP-16/QAM-16 and 4×100Gb/s QAM-16-OFDM have relative complexities of 1:5.4:5.7 and consume power of 0.71, 0.67 and 0.75 times that of 16×25Gb/s NRZ benchmark links. OCIS codes: (060.2330) Fiber optics communications; (060.4080) Modulation;

Orthogonal Frequency Division Multiplexing (OFDM) has been widely adopted in many applications due to its good spectral performance and low sensitivity to impulse noise and multipath channels. It has been widely adopted and standardized in many applications today. It is well known in OFDM that a cyclic prefix (CP) is appended to each symbol in order to mitigate the effect of Inter-Symbol-Interf...

Complies with the regulations of this University and meets the accepted standards with respect to originality and quality. Coherent detection employing high modulation formats has become one of the most attractive technologies for long-haul transmission systems due to the high power and spectral efficiencies. Appropriate digital signal processing (DSP) is used to equalize and compensate for dis...

We propose a new nonlinear optical loop mirror based configuration capable of regenerating regular rectangular quadrature amplitude modulated (QAM) signals. The scheme achieves suppression of noise distortion on both signal quadratures through the realization of two orthogonal regenerative Fourier transformations. Numerical simulations show the performance of the scheme for high constellation c...

In this letter, we propose a polarity decision carrier recovery algorithm that is useful for carrier acquisition in high order QAM. The PD (Phase Detector) output and its variance characteristic are mathematically derived and the simulation results are presented. The proposed algorithm shows enhanced acquisition performance especially for large frequency offset. key words: carrier recovery, QAM...

Recently, multiple-input–multiple-output (MIMO) relay networks have been an active area of research, particularly with combining single transmit antenna selection (TAS) and receiver maximal ratio combining (MRC). Moreover, generalorder rectangular quadrature amplitude modulation (QAM) has received much attention for its high spectral efficiency and flexible modulation scheme. However, the analy...

DWT-OFDM has drawn most of the attention in the field of wireless communication. But to provide better efficiency of the communication channel, error correction codes are proposed. In this paper, we investigated the performance of 1⁄2 rate convolution encoded discrete wavelet transform based orthogonal frequency division multiplexing system (DWT-OFDM) over Additive White Gaussian noise channel ...

— A construction for a family, Q M 2 , of low-correlation sequences over QAM alphabet of size M 2 = 2 2m is presented with maximum nontrivial normalized correlation parameter bounded above by a √ N , where N is the period of the sequences in the family and where a ranges from 2.10 in the case of 64-QAM modulation to 2.76 for large m. Interestingly, along the way, for the particular case of the ...

Optimization of the switching thresholds for constant-power adaptive five-mode M -ary quadrature amplitude modulation (M -QAM) transmission with an amplify-and-forward (AF) relay network is developed. The optimization criterion is the maximization of spectral efficiency subject to an average bit-error-rate (BER) constraint. This approach results in a constant-BER variable-rate M -QAM AF relay s...

The purpose of this paper is to derive closed-form expressions for the error rate performance of coherent H-ary Quadrature Amplitude Modulated (QAM> systems in the presence of an additive combination of Gaussian and highly impulsive noise, using the powerful Fourier-Bessel series expansion method. The emplo:'ed model of the impulsive noise, which closely models atmospheric and/or man-made noise...