Low-PMEPR OFDM transmission with an iterative receiver technique for cancellation of nonlinear distortion

2007 IEEE 66th Vehicular Technology Conference

Araujo

2007

Self Cite

-We consider MC-CDMA schemes, with reduced envelope fluctuations. Both CP-assisted (Cyclic Prefix) and ZP (Zero-Padded) MC-CDMA schemes are addressed. We develop Turbo FDE (Frequency-Domain Equalization) schemes, combined with cancelation of nonlinear distortion effects. The proposed turbo receivers allow significant performance improvements at low and moderate SNR, even when the transmitted signals have reduced envelope fluctuations.

Section: Performance Resultsmentioning

confidence: 99%

Turbo Equalization with Cancellation of Nonlinear Distortion Effects for CP-Assisted and Zero-Padded MC-CDMA Signals

2007 IEEE 66th Vehicular Technology Conference

Araujo

2007

Self Cite

“…The performances could be further improved if the feedback loop uses the channel decoder outputs instead of the MUD outputs, as suggested for OFDM schemes in [16]. This is especially important if we decrease the clipping level, to reduce further the PMEPR of the transmitted signals.…”

Section: Discussionmentioning

confidence: 99%

Joint Multiuser Detection and Cancelation of Nonlinear Distortion Effects for the Uplink of MC-CDMA Systems

2006 IEEE 17th International Symposium on Personal, Indoor and Mobile Radio Communications

2006

In this paper we consider the uplink transmission in MC-CDMA systems (MultiCarrier Coded Division Multiple Access). To reduce the envelope fluctuations of the transmitted signals, the MC-CDMA signal associated to each MT (Mobile Terminal) is submitted to a clipping device,followed by a frequency-domain filtering operation. We define an iterative receiver that jointly performs the MUD (MultiUser Detection) and the estimation and cancelation of the nonlinear distortion effects that are inherent to the transmitted signals.Our performance results show that the proposed receiver structures allow good performances, even for severely timedispersive channels and/or when a low-PMEPR is intended for each MT.

“…Is should also be noted that the data estimates employed in the feedback loop could be provided by a suitable channel decoder (as suggested in [13] for OFDM schemes), which is especially recommendable for scenarios where the nonlinear distortion effects are very sttrong (e.g., when the clipping level is very low and/or the nonlinear and filtering operations are repeated, in an iterative way (as in [12])). The performances on timedispersive channels could be further improved if the linear FDE is replaced by an IB-DFE (Iterative Block Decision Feedback Equalizer), as proposed in [14].…”

Section: Conclusion and Final Remarksmentioning

confidence: 99%

An Iterative Detection Technique for DS-CDMA Signals with Strong Nonlinear Distortion Effects

IEEE Vehicular Technology Conference

2006