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Adaptive Overlap-Add Equalization For Mb-Ofdm Ultra-Wideband, Darryn Lowe, Xiaojing Huang
Adaptive Overlap-Add Equalization For Mb-Ofdm Ultra-Wideband, Darryn Lowe, Xiaojing Huang
Faculty of Informatics - Papers (Archive)
A zero-pad can be used with orthogonal frequency division multiplexing (OFDM) for low-complexity robustness against multipath interference. In this paper, we use adaptive overlap-add (OLA) equalization for improvements of up to 0.6 dB improvement when used with multi-band OFDM (MB-OFDM) ultra-wideband in multipath channels. A theoretical model that relates the size of OLA window to post-equalizer signal-to-noise ratio is derived. An approximating algorithm is then developed that is suitable for low-complexity implementation, with Monte Carlo simulations used to quantify the performance improvements. We conclude that adaptive OLA equalization is computationally simple and can be implemented while remaining fully compliant with …
Ultra-Wideband Mb-Ofdm Channel Estimation With Complementary Codes, Darryn Lowe, Xiaojing Huang
Ultra-Wideband Mb-Ofdm Channel Estimation With Complementary Codes, Darryn Lowe, Xiaojing Huang
Faculty of Informatics - Papers (Archive)
In this paper, we design complementary codesets that significantly improve the quality of channel estimation in orthogonal frequency division multiplexing (OFDM) communication systems, with a focus on the recent MB-OFDM ultra-wideband (UWB) standard. The proposed time-domain OFDM channel estimation technique incurs only a nominal increase in computational complexity and is able to be readily retrofitted into the existing MB-OFDM standard. The underlying complementary codesets, found via an evolutionary algorithm, combine with the existing preamble synchronization sequences to yield asymptotically ideal auto-correlation functions (ACFs). We show how improvements exceeding 1 dB can be achieved in end-to-end packet error rate relative to …
Adaptive Low-Complexity Mmse Channel Estimation For Ofdm, Darryn Lowe, Xiaojing Huang
Adaptive Low-Complexity Mmse Channel Estimation For Ofdm, Darryn Lowe, Xiaojing Huang
Faculty of Informatics - Papers (Archive)
In this paper we present extremely low-complexity adaptive infinite impulse response (IIR) filters that approximate minimum mean square error (MMSE) channel estimation in orthogonal frequency-division multiplexing (OFDM) systems. We show how the packet error rate (PER) can be significantly improved over conventional zero-forcing (ZF) estimation without incurring a significant increase in computational complexity. All quantitative results are provided in the context of multi-band OFDM (MB-OFDM) ultra-wideband (UWB) with standard IEEE channel models.