Multi-carrier code division multiple access (MC-CDMA) is modulation method for high speed data communication. The usage of MIMO MCCDMA can significantly improve the performance of wireless communication system. This paper presents the analysis of Multi Input Multi Output MultiCarrier CDMA system performance for BPSK, QPSK, MSK modulation over AWGN channel and Rayleigh channel. This represents t...

A robust peak-power reduction technique called active constellation extension (ACE) reduces the peak-to-average power ratio (PAPR) of single-input single-output (SISO) orthogonal frequency-division modulated (OFDM) signals by extending the outer constellation points in a way that minimizes the PAPR of an OFDM transmit signal, without reducing the bandwidth or increasing bit error rate (BER). Re...

A number of critical issues for dual-polarization single- and multi-band optical orthogonal-frequency division multiplexing (DP-SB/MB-OFDM) signals are analyzed in dispersion compensation fiber (DCF)-free long-haul links. For the first time, different DP crosstalk removal techniques are compared, the maximum transmission-reach is investigated, and the impact of subcarrier number and high-level ...

Digital modulation plays a significant role in efficient wireless communication. It allows the transmission of digital data via air on high frequency carrier waves. The worst case communication channel is usually in the urban environment where there are many obstacles. Due to the obstacles and reflectors, the transmitted signal arrives at the receiver from various directions over a multiplicity...

This paper analyzes the effects of jitter on the GPS and Galileo navigation signals. Jitter effects have usually been modelled as additive noise, based on a sinusoidal input signal, and limits the achievable Signal-to-Noise Ratio (SNR). Analysis shows that psec-level jitter specifications are required in order to keep jitter noise well below the thermal noise for software radio satellite naviga...

Coherent systems based on QPSK rely on differential encoding to avoid catastrophic error propagation. A simple solution for soft differential decoding is presented that limits the penalty after FEC to 0.75dB, similar to pre-FEC binary differential decoding.

where p(t) is a (typically real valued) pulse shape, and the ck are QAM symbols drawn from a finite collection of complex numbers called a constellation based on input bits to be communicated over the channel. Some example QAM constellations include 4-QAM (a.k.a QPSK){±1± j}, 16-QAM {±a± jb} with a, b ∈ {1, 3}, 64-QAM {±a + jb} with a, b ∈ {1, 3, 5, 7}, and 256-QAM {±a ± jb} with a, b ∈ {1, 3, ...

We demonstrate fiber nonlinearity mitigation by using multiple optical phase conjugations (OPCs) in the WDM transmission systems of both 8 × 32-Gbaud PDM QPSK channels and 8 × 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC in terms of nonlinear threshold and a best achievable Q2 factor after transmission. In addition, after an even nu...