Truncating and oversampling OFDM signals in white Gaussian noise channels

This work introduces a modified version of the orthogonal frequency division multiplexing (OFDM) signal by truncating OFDM symbols in the time domain. Sub-carriers are no longer orthogonally packed in the frequency domain as time samples are only partially transmitted, leading to improved spectral efficiency. In this work, mathematical expressions are derived for the newly proposed Truncated OFDM (TOFDM) signal, followed by interference analysis and performance comparisons. We also consider optimal and practical decoder architectures. Results from a Sphere Decoder-based decoder indicate that truncation length can significantly affect the error performance. With short truncation length, using a purpose designed detector, signals can be recovered even with truncated symbol transmission.

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