Spectrum efficient data transmission is of key interest for high capacity optical communication systems considering the limited available bandwidth. Transmission of the high speed signal with higher-order modulation formats within the Nyquist bandwidth using coherent detection brings attractive performance advantages. However, high speed Nyquist signal generation with high order modulation form...

A design method for recursive space-time trellis codes and parallel-concatenated space-time turbo coded modulation is proposed that can be applied to an arbitrary existing space-time trellis code. The method enables a large, systematic increase in coding gain while preserving the maximum transmit diversity gain and bandwidth efficiency property of the considered spacetime trellis code. Applying...

For a general class of constant-energy trellis-coded modulation schemes with 2 states, necessary and suÆcient conditions to guarantee that a maximumlikelihood sequence estimator can decode each symbol with a xed delay of symbols are derived. Additive white Gaussian noise is assumed. MSK is a special case that belongs to the family of modulation schemes with = 1. It is shown that when these cond...

This paper has presented the different advanced modulation techniques for free space optical (FSO) communication systems transmission efficiency enhancement and signal quality estimation in weak, medium and strong turbulence communication channels. The bandwidth and power efficiency issues in free space optics (FSO) transmissions are addressed under non return to zero on-off keying (NRZ-OOK), r...

Wireless sensor nodes have a limited amount of energy resource that determines their lifetime. So, Energy efficient modulation techniques are of paramount importance for wireless sensor communication (WSC). Also the type and behavior of the pulse shaping filters used, influences the performance of the modulation scheme. The Alternating Quadratures Differential Binary Phase Shift Keying (AQ-DBPS...

Quantum-dot (QD) lasers exhibit many useful properties such as low threshold current, temperature and feedback insensitivity, chirpless behavior, and low linewidth enhancement factor ( H-factor). Although many breakthroughs have been demonstrated, the maximum modulation bandwidth remains limited in QD devices, and a strong damping of the modulation response is usually observed pointing out the ...

We demonstrate temporal imaging with -42.6x time magnification of 200 ps frames with subpicosecond resolution for waveforms containing 2.5 Gb/s modulated picosecond pulses. 852 GHz signal bandwidth is captured single-shot at 104 MHz frame rates. ©2009 Optical Society of America OCIS codes: (320.7100) Ultrafast measurements; (190.4410) Nonlinear optics, parametric processes

This article is intended to serve as a “road map” for outlining typical steps to be considered in meeting the bandwidth, power, and error-performance requirements of a digital communication system. The criteria for choosing modulation and coding schemes, based on whether a system is bandwidth-limited or power-limited, are reviewed for several system examples, and the article emphasizes the subt...

An expanded effort is underway to support the evolution of the UMTS standard to meet the rapidly developing needs associated with wireless Internet applications. The support of High-Speed Downlink Packet Access (HSDPA) is provided by means of a new, shared channel called High Speed Downlink Shared Channel (HSDSCH) which is enabled by a number of performance enhancing technologies such as Adapti...