tailieunhanh - Báo cáo hóa học: " On the EVM computation of arbitrary clipped multi-carrier signals"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: On the EVM computation of arbitrary clipped multi-carrier signals | Kotzer and Litsyn EURASIP Journal on Advances in Signal Processing 2011 2011 36 http content 2011 1 36 o EURASIP Journal on Advances in Signal Processing a SpringerOpen Journal RESEARCH Open Access On the EVM computation of arbitrary clipped multi-carrier signals Igal Kotzer and Simon Litsyn Abstract A common figure of merit in multi-carrier systems is the error vector magnitude EVM . A method for EVM computation of a multi-carrier signal without any underlying model . the Gaussianity assumption was proposed in a previous work of the authors. However it addressed only the case of identical constellations and power loadings in all tones. In practice however the constellation and power loading may vary among the tones . boosted pilots waterfilling and zero guard bands . Here the earlier approach is generalized in such a way that it is able to accommodate for an accurate analytical EVM computation in the cases of power loading and different constellations for different tones. Moreover the derivation is valid for a general magnitude clipping function so that any realistic clipper can be plugged in. 1 Introduction The use of multi-carrier MC communication schemes . OFDM DMT etc. is very common nowadays due to its ability to cope well with channel interference while keeping the receiver complexity low the ease of spectral mask shaping and high spectral efficiency. However one of MC scheme s greatest drawbacks is the high peak-to-average power ratio PAPR caused by various degrees of coherent summation in the signal generation using IFFT 1 . Thus systems utilizing MC communications must work with a large back-off in the high-power amplifier HPA which reduces both the efficiency of the HPA and the average power transmitted or risk clipping. Based on the understanding that clipping is a nonlinear operation causing both in-band and out-of-band spectral noise and thus is an undesirable operation methods for reducing the PAPR were devised. For a