Pre-equalized and Spectrally Precoded OFDM
Journal
IEEE Transactions on Vehicular Technology
Date Issued
2022
Author(s)
Abstract
When the channel state information is available, frequency-domain precoding is studied for rectangularly-pulsed orthogonal frequency-division multiplexing (OFDM) using cyclic prefix over dispersive channels to provide extremely compact signal spectrum, enhanced achievable data rate (ADR), and reduced peak-to-average power ratio (PAPR) jointly. With a precoding rate not larger than 1-2I/N, a general precoder form is first developed for the transmitted N-subcarrier OFDM signal to provide extremely small baseband power spectral sidelobes decaying asymptotically as f^{-2I-2} or faster, with f being the frequency, and thus achieve high spectrum compactness while yielding reduced PAPR. Incorporating the channel response, a particular spectral precoder following the general form is then designed to maximize the ADR under a fixed transmitted power. When a small out-of-band power proportion is required to guarantee spectrum compactness, the proposed pre-equalized and spectrally-precoded OFDM system can provide much higher ADR per unit bandwidth than pre-equalized OFDM, spectrally-precoded OFDM, and nonprecoded OFDM. When the low-complexity receiver is mandatory, a systematically pre-equalized and spectrally precoded OFDM system is also developed to achieve enhanced ADR, extremely high spectrum compactness, and low-complexity receiver operation by trading transmission power on cancellation subcarriers. IEEE
Subjects
achievable data rate; channel pre-equalization; Frequency diversity; Matrix decomposition; OFDM; Orthogonal frequency-division multiplexing; Peak to average power ratio; Precoding; Receivers; sidelobe suppression; Symbols
Other Subjects
Channel state information; Communication channels (information theory); Equalizers; Frequency domain analysis; Signal receivers; Achievable data rate; Channel pre-equalization; Data-rate; Frequency diversity; Matrix decomposition; Orthogonal frequency-division multiplexing; Peakto-average power ratios (PAPR); Pre-equalization; Precoding; Receiver; Side-lobe suppression; Symbol; Orthogonal frequency division multiplexing
Type
journal article