MMSE decision feedback equalization of pulse position modulated signals

• Published in: 2004 IEEE Itnernational Conference on Communications Vol. 5; pp. 2648 - 2652 Vol.5
• Main Authors: Klein, A.G., Johnson, C.R.
• Format: Conference Proceeding
• Language: English
• Published: Piscataway, New Jersey IEEE 2004
• Subjects: Additive noise; Applied sciences; Computational modeling; Computer errors; Decision feedback equalizers; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Information, signal and communications theory; Intersymbol interference; Modulation, demodulation; Pulse modulation; Random processes; Signal and communications theory; Signal, noise; Stochastic processes; Telecommunications and information theory; Ultra wideband technology; Vectors; Performance evaluation; Simulation; Intersymbol interference; Modulation; Descent method; Modulated signal; Decision feedback equalizers; Stochastic method; Gradient method; Ultra wide band; Mean square error
• ISBN: 0780385330; 9780780385337
• DOI: 10.1109/ICC.2004.1313011

We propose a minimum mean squared error (MMSE) decision feedback equalizer (DFE) for pulse position modulated (PPM) signals in the presence of intersymbol interference (ISI). While traditional uses of PPM may not have ISI, PPM is a candidate modulation scheme for ultra wideband (UWB), and may experience ISI in that application. First, we review the previous work on the subject which used the zero-forcing criterion under strict assumptions about the channel and equalizer lengths. Then, we derive a computationally efficient MMSE equalizer which removes these restrictions, and is suitable for use with stochastic gradient descent algorithms. Finally, we demonstrate the performance of the proposed equalizer with simulations.