On the Wavelet OFDM Performance in Time Variant Channels: Choosing the Number of DWT Iterations
نویسنده
چکیده
The influence of the number of Discrete Wavelet Transform (DWT) iterations on a wavelet OFDM (WOFDM) system performance is studied in this paper. The WOFDM transmission is tested on a flat, time variant radio channel. Basically, the number of DWT iterations coincides with the number of transmission scales used. Our simulations show that by increasing the value of this parameter, the BER performance degrades. This result is explained by the fact that a small number of iterations keeps the duration of the transmitted symbols significantly shorter than the coherence time of the channel. Key-Words: WOFDM, DWT, iterations, time variability
منابع مشابه
Using WPT as a New Method Instead of FFT for Improving the Performance of OFDM Modulation
Orthogonal frequency division multiplexing (OFDM) is used in order to provide immunity against very hostile multipath channels in many modern communication systems.. The OFDM technique divides the total available frequency bandwidth into several narrow bands. In conventional OFDM, FFT algorithm is used to provide orthogonal subcarriers. Intersymbol interference (ISI) and intercarrier interferen...
متن کاملEvaluation Performance of OFDM Mutlicarrier Modulation over Rayleigh and RicianStandard Channels Using WPT-OFDM Modulations
Last years, Wavelet Packet Modulation (WPM) or Wavelet Packet Transform based Orthogonal Frequency Division Multiplexing (WPT-OFDM) have been introduced to wired and wireless communication fields as efficient Multicarrier Modulation (MCM) techniques. The wavelets have interesting features such as flexibility, compatibility and localization in both time and frequency domains with no need to use ...
متن کاملProposed Pilot Pattern Methods for Improvement DVB-T System Performance
Recently, orthogonal frequency division multiplexing (OFDM) has been extensively used in communications systems to resist channel impairments in frequency selective channels. OFDM is a multicarrier transmission technology in wireless environment that use a large number of orthogonal subcarriers to transmit information. OFDM is one of the most important blocks in digital video broadcast-terrestr...
متن کاملChannel Effect Compensation in OFDM System under Short CP Length Using Adaptive Filter in Wavelet Transform Domain
Channel estimation in communication systems is one of the most important issues that can reduce the error rate of sending and receiving information as much as possible. In this regard, estimation of OFDM-based wireless channels using known sub-carriers as pilot is of particular importance in frequency domain. In this paper, channel estimation under short cyclic prefix (CP) in OFDM system is con...
متن کاملFPGA based DWT-IDWT implementation of OFDM on UWB Systems
Orthogonal Frequency Division Multiplexing/Modulation (OFDM) is widely used for symbol level modulationdemodulation in communication systems for a high data rate low distance range applications. OFDM refers to both multiplexing and modulation technique to transmit parallel data using orthogonal carriers in the same or different frequency bands. In this work, DWT-OFDM is modeled which aims to se...
متن کامل