Multicarrier-signal design with low peaks and low out-of-band power

Projecte fet en col.laboració amb el Department of Electrical and Information Technology. Lund UniversityThe high peak-to-average power ratio (PAPR) and the high out-of-band power (OBP) are two major drawbacks of multicarrier communication systems. Many PAPR reduction and OBP supression techniques have been proposed in the literature whereas not much has been proposed regarding the jointly reduction performance. This thesis focuses on joint reducing time-domain peaks and out-of-band leakage of OFDM signals. The resulting algorithm combines the bene ts of both methods and yields better results than each method does separately

Multicarrier-signal design with low peaks and low out-of-band power

Projecte fet en col.laboració amb el Department of Electrical and Information Technology. Lund UniversityThe high peak-to-average power ratio (PAPR) and the high out-of-band power (OBP) are two major drawbacks of multicarrier communication systems. Many PAPR reduction and OBP supression techniques have been proposed in the literature whereas not much has been proposed regarding the jointly reduction performance. This thesis focuses on joint reducing time-domain peaks and out-of-band leakage of OFDM signals. The resulting algorithm combines the bene ts of both methods and yields better results than each method does separately

Joint design of PAPR, PICR and OBP in OFDM systems

Orthogonal frequency division multiplexing (OFDM) technique has been adopted by many existing and future wireless communication systems for high-speed data transmission. However, a major problem of OFDM systems is the high peak-to-average power ratio (PAPR) of OFDM signals, which results in inefficient operations of nonlinear devices in the system such as power amplifiers (PAs). On the other hand, at the receiver end, frequency offset, caused by Doppler frequency shifts, mismatched oscillators, or a fast fading channel, destroys the orthogonality among subcarriers and results in inter-carrier interference (ICI), thus degrades the detection performance of OFDM systems. Analogous to the definition of PAPR, the peak interference-to-carrier ratio (PICR) is defined to represent the effect of ICI. In addition, due to the sidelobes of modulated subcarriers, OFDM systems also suffer from high out-of-band power (OBP) radiations. High OBP results in the need for wide guard band and thus inefficient usage of frequency band

Suppression of Mutual Interference in OFDM Based Overlay Systems

A promising appraoch for overcoming spectrum scarcity are overlay systems that share a frequency band with already existing licensed systems by using the spectral gaps left by the licensed systems. Due to its spectral efficiency and flexibility orthogonal frequency-division multiplexing (OFDM) is an appropriate modulation technique for overlay systems. To enable a successful co-existence, techniques for suppressing mutual interferences between the overlay and the licensed system are proposed