The effectiveness of the recently proposed adaptive Maximum A Posteriori (MAP) receiver in Cusani and Mattila is verified for digital HF links between mobile and/or fixed units. Following Cusani and Mattila, a suitable MAP algorithm is employed to compute Symbol-by-Symbol (SBS) the A Posteriori Probabilities (APP’s) of the channel state; from these, the detected data stream is obtained. The sam...

We review our recent work on ultra-long-haul wavelength division multiplexed (WDM) transmission with high spectral efficiency (SE) employing tight pre-filtering and multi-symbol detection. We start the discussion with a theoretical evaluation of the SE limit of pre-filtered modulation in optical fiber communication systems. We show that pre-filtering induced symbol correlation generates a modul...

We show that the full symbol of the Dirichlet to Neumann map of the k-form Laplace’s equation on a Riemannian manifold (of dimension greater than 2) with boundary determines the full Taylor series of the metric at the boundary. This extends the result of Lee and Uhlmann for the case k = 0. The proof avoids the computation of the full symbol by using the calculus of pseudo-differential operators...

In this paper we describe a trellis representation of variable length coded data which is capable of being used for bit-level or symbol-level maximum a posteriori (MAP) decoding of variable length codes (VLC). A bit-level soft-input/soft-output module is derived and is applied in an iterative decoding structure consisting of an outer variable length code and an inner convolutional code. Due to ...

An expert system for analysis and recognition of general symbols is introduced. The system uses the structural pattern recognition technique for modeling symbols by a set of straight lines referred to as segments. The system rotates, scales and thins the symbol, then extracts the symbol strokes. Each stroke is transferred into segments (straight lines). The system is shown to be able to map sim...

The tracking (mean-square timing-error) performance of a linearized datatransition tracking loop (LDTTL) is presented. The difference between the LDTTL and the conventional DTTL is that the hard-limiter nonlinearity in the conventional DTTL’s inphase arm is replaced by a linear device, as suggested by the maximum a posteriori (MAP) open-loop estimate of symbol timing at low symbol signal-to-noi...

We consider families of analytic area preserving maps depending on two pa rameters the perturbation strength and the characteristic exponent h of the origin For these maps are integrable with a separatrix to the origin whereas they asymptote to ows with homoclinic connections as h For xed and small h we show that these connections break up The area of the lobes of the resultant turnstile is giv...

UNLABELLED The frequent and fluent use of symbols is a distinguishing characteristic of human thought and communication. Symbols free us from the bounds of our own direct experience and allow us to learn about the world from others. To use a symbol, children need to (1) understand the intention that led to the creation and use of the symbol, and (b) how the symbol relates to its referent. For e...