An essential parameter in determining the system power budget in an optical transmission system is optical receiver sensitivity, defined as the minimum average optical power for a given bit-error rate (BER). When designing a good optical receiver, it is critical to understand the different parameters that will impair overall receiver sensitivity. This article provides an indepth analysis of com...

In this study, we consider the ways for concatenating the intersymbol interference (ISI) detector with a q-ary lowdensity parity-check (LDPC) decoder for transmissions over partial response (PR) channels. LDPC codes allow achieving performance close to the channel capacity in additive white Gaussian noise channels, while designing receivers employing these codes for transmissions over channels ...

In this paper we present two throughput enhancing detection schemes for OFDM, all using the Frequency Domain Channel Length Indicator (FCLI) algorithm for improved channel estimation and joint mobile channel impulse response length estimation. At first we introduce a novel optimized detection scheme for guardinterval-free OFDM reception. In contrast to traditional OFDM, omitting the guard inter...

A histogram-based technique allows to estimate the bit error probability (BEP) of an optical signal suffering from distortion. At 10Gbit/s, we obtain good results even for high optical signal-to-noise ratios, i.e. for low BEP. Introduction A common technique to estimate the bit error probability (BEP) in optical communication systems uses a histogram generated by sampling the photocurrent corru...

| The Viterbi algorithm (VA) can be reformulated such that the calculations can be performed over a set of independent parallel trellises for a class of sparse channels. This new algorithm named the parallel trellis Viterbi algorithm (PTVA) reduces the complexity of the Viterbi algorithm, however, it has no loss in performance for the special class of intersymbol interference (ISI) channels. Pr...

A novel noncoherent receiver for M{ary di erential phase shift{keying (MDPSK) signals transmitted over intersymbol interference (ISI) channels is presented. The noncoherent receiver consists of a linear equalizer and a decision{feedback di erential detector. A signi cant performance gain over a previously proposed noncoherent receiver can be observed. For an in nite number of feedback symbols, ...

In orthogonal frequency division multiplexing (OFDM) systems, a time-domain equalizer (TEQ) is used to reduce the intersymbol interference (ISI) by shortening the channel impulse response when the channel length is larger than cyclic prefix (CP) length. However, conventional channel shortening methods may have frequency notch problem which will causes significant system performance degradation....

Introduction: Adaptive equalisers have been widely employed to mitigate the effect of intersymbol interference (ISI) and to retrieve a transmitted signal u[n] from a distorted received copy x[n] at the output of a channel c[n] in the presence of channel noise v[n], whereby Fig. 1 illustrates a general block diagram for channel equalisation [1]. For a minimum mean square equaliser (MMSE), adapti...

We propose a finite impulse response (FIR) minimum mean squared error (MMSE) decision feedback equalizer (DFE) for orthogonal multipulse modulated signals received through a multipath channel. Our system model accounts for both the loss of orthogonality caused by the multipath channel as well as intersymbol interference (ISI). First, we review previous work on the subject which used the zero-fo...

In this paper we present an adaptive BlockBased EigenVector Algorithm (BBEVA) for blind equalization of time-varying multipath fading channels. In addition we assess the performance of the new algorithm for different configurations and compare the results with the least mean squares (LMS) algorithm. The new algorithm is evaluated in terms of intersymbol interference (ISI) suppression, mean squa...