Sensitivity Gains by Mismatched Probabilistic Shaping for Optical Communication Systems

A Mismatched Joint Source-Channel Coding Perspective of Probabilistic Amplitude Shaping: Achievable Rates and Error Exponents

Probabilistic Amplitude Shaping (PAS) is a novel method of reliable commmunication over channels with non-uniform capacity achieving input distribution. The encoder of PAS is a concatenation of a distribution matcher with systematic encoding of a Forward Error Correction (FEC) code whereas the PAS decoder is a concatenation of a mismatched FEC decoder and dematcher. In recent works PAS has been...

Wireless Optical Communication Systems WIRELESS OPTICAL COMMUNICATION SYSTEMS

Achievable Rates for Probabilistic Shaping

For a layered probabilistic shaping (PS) scheme with a general decoding metric, an achievable rate is derived using Gallager’s error exponent approach. Several instances for specific decoding metrics are discussed, including bit-metric decoding, interleaved coded modulation, and hard-decision decoding. It is shown that important previously known achievable rates can also be achieved by layered ...

Theoretic Shaping Bounds for Single Letter Constraints and Mismatched Decoding

Shaping gain is attained in schemes where a shaped subcode is chosen from a larger codebook by a codeword selection process. This includes the popular method of Trellis Shaping (TS), originally proposed by Forney for average power reduction. The decoding process of such schemes is mismatched, since it is aware of only the large codebook. This study models such schemes by a random code construct...

Optical Design of Laser Beam Shaping Systems

An overview of the history and current practices of laser beam shaping is presented. When diffraction effects are not important, geometrical methods for laser beam shaping (ray tracing, conservation of energy within a bundle of rays, and the constant optical path length condition) can be used to determine system configurations, including aspheric elements and spherical-surface GRIN lenses, whic...