Generation of OFDM signal with envelop pulse-width modulation (EPWM) transmitter employing 2nd-order delta-sigma modulator
OFDM achieves high spectral efficiency in wireless communication systems. However, it is difficult ti achieve high power efficiency because of its large PAPR. Envelope Pulse-Width Modulation (EPWM) transmitters have been proposed to obtain high power efficiency for the amplification of OFDM signals....
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| Main Authors: | , , , |
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| Format: | text |
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Animo Repository
2008
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| Subjects: | |
| Online Access: | https://animorepository.dlsu.edu.ph/faculty_research/12564 |
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| Institution: | De La Salle University |
| Summary: | OFDM achieves high spectral efficiency in wireless communication systems. However, it is difficult ti achieve high power efficiency because of its large PAPR. Envelope Pulse-Width Modulation (EPWM) transmitters have been proposed to obtain high power efficiency for the amplification of OFDM signals. This paper proposes an EPWM transmitter which employs the 2nd order Δ-∑ modulator with a null-response frequency. Expression for quantization noise power is theoretically derived to estimate in-band and adjacent channel quantization noise power. The power spectral density (PSD) of the IEEE 802.11a OFDM signal generated with the transmitter is calculated changing the null-response frequency. The adjacent channel leakage power ratio (ACLR) of the OFDM output signal is calculated from the PSD. It is shown that the null-response frequency of 20 MHz give the minimum ACLR for the transmitter. |
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