Motivated by modern applications of light detection and ranging (LIDAR), we study the model an optical receiver based on avalanche photo-diode (APD), followed electronic circuitry for reflected signals estimation their delay. This is known to be quite complicated as it consists at least three different types noise: thermal noise, shot multiplicative noise (excess noise) that stems from random g...

Type-based receivers assume no a priori channel model, and were previously shown to be e ective in direct-sequence spread spectrum communications. In this paper, we investigate the macro-diversity combining of multiple type-based receivers in single-mobile-user reception (BPSK). We present a method for the exact calculation of the bit error rate of type-based receivers in this scenario. Maximal...

We study coherent binary direct-sequence code division multiple access (DS-CDMA) systems operating over frequency-selective Nakagami fading channels. In particular a performance comparison between maximal-ratio combining (MRC) and equal-gain combining (EGC) RAKE receivers is considered. For interference limited systems, perfect MRC RAKE receivers can accommodate about 5m=(5m ? 1) more users tha...

It is shown through physics-based Monte Carlo simulations of avalanche photodiode (APD) LADAR receivers that under typical operating scenarios, Geiger-mode APD (GmAPD) flash LADAR receivers may often be ineffective. These results are corroborated by analysis of the signal photon detection efficiency and signal-to-noise ratio metrics. Due to their ability to detect only one pulse per laser shot,...

This chapter presents one of the primary contributions of this dissertation: a mathematical model to analyze and evaluate noise-like spectrum-sliced systems which employ conventional PIN receivers, or as proposed in this dissertation, optical preamplifier receivers. As discussed in previous chapters, spectrum-slicing provides a low-cost alternative to the use of multiple coherent lasers for WDM...

Several optical AM-PSK partial response signalling (PRS) systems, also known as correlative level signalling, are evaluated through numerical simulation. Discussion is focussed to three-level PRS systems, namely duobinary, modified duobinary and dicode. Suitable transmitter implementation, taking advantage of the phase of the optical wave, allows the use of standard binary intensity modulation ...

Maximum likelihood sequence estimation (MLSE) has been proposed in earlier literature to combat the effects of nonlinear dispersion in intensity modulation/direct detection (IM/DD) optical channels. In this paper, we develop a theory of the bit error rate (BER) of MLSE-based IM/DD receivers operating in the presence of nonlinear dispersion and amplified spontaneous emission (ASE) noise. We focu...

Multi-user receivers in asynchronous Direct Sequence Code Division Multiple Access (DS-CDMA) systems require the knowledge of several parameters such as timing delay between users. The goal of this work is to present a QHDU IDU resistant joint multi-user synchronization and detection algorithm for DSCDMA systems. The solution is based on the Conditional Maximum Likelihood (CML) estimation metho...