Multi-Carrier Waveform Based On Compressive Sensing

Multi-carrier transmission technology is a key technology in physical layer of wireless communication.It is necessary to improve the spectral efficiency of new multi-carrier transmission system.Currently,there are many researches about new multi-carrier waveform.Most of these researches improve spectral efficiency by increasing the number of frequency domain filters and decrease out-of-band leakage.However,utilizing the filter to improve spectral efficiency leads to high complexity.In this thesis,time domain characteristic of multi-carrier waveform is studied for new waveform with high spectral efficiency.Compressive sensing is an effective method to achieve signal sampling and compression,which is widely used in communication systems.Firstly,this thesis combines compressive sensing and multi-carrier transmission technology,utilizing the time domain characteristics in multi-carrier waveform.Selecting a part of orthogonal subcarriers from the traditional multi-carrier system,then forming over-complete dictionary elements after aliasing and extending those subcarriers.It can improve the sparsity of subcarrier modulation signal by designing the multi-carrier waveforms.Comparing with the traditional multi-carrier system,this model can not only improve the bit error rate,but also enhance spectral efficiency due to the number of orthogonal subcarriers required is less.Secondly,according to the wavelet transform adaptability for image data,this thesis proposed a multi-carrier waveform which is more suitable for transmission.We designed non-orthogonal wavelet multi-carrier waveform and combined it with over-complete dictionary to improve image sparsity.The simulations show that this method can reduce the interference of channel noise and improve the quality of image.Moreover,it has lower peak to average power ratio compared to the traditional multi-carrier transmission.