Research On Continue Phase Modulation Technology For Visible Light Communication And Pseudo-Noise Ranging

With the accelerating trend of Internet business like mobile payment and online socializing blending into our daily life,and the development of Internet of thing(IOT)and virtual reality(VR),new requirements are put forward for the capability of smart device's data transmission.Besides,with further exploration and utilization of outer space,such requirements are also extended to the deep-space communication device.It means the present-available wireless spectrum resource will facing all-dimensional challenge of signal intensity.In terms of these views,the visible light communication(VLC)technology that expending the resource of daily-used wireless spectrum,the continue phase modulation(CPM)technology with efficient spectrum utilization,along with the deriving modulation technology combining CPM and pseudo-noise(PN)code,therefore,possess the tremendous value for research.This paper conducts the research on CPM-VLC scheme and CPM/PN signal,which includes following aspects:(1)The system-level realization of CPM-VLC scheme is demonstrated,including its transmitted signal model,software processing module and hardware deceives.The light emitting diode's(LED)transmitting power advantage of CPM-VLC over VLC scheme applying orthogonal frequency-division multiplexing(OFDM)when holding the same bit error rate(BER)is verified.(2)Considering the visible light channel characteristic in different scene,a receiver algorithm that simultaneously coping with line of sight(LOS)channel and multipath channel is developed.It contains three sub-algorithms:channel estimation algorithm,frequency domain equalization algorithm and signal reconstruction algorithm.The channel estimation algorithm calculates the parameters of multipath channel(if it is).The frequency domain equalization algorithm eliminates the multipath effect of received signal.The reconstruction algorithm reconstructs the discrete equalized results.These solve the incompatibility between theoretical frequency equalization algorithm and LOS channel receiver scheme.The computation complexity of sub-algorithm are reduced by simplifying the decomposing pulses.And the ill-posed matrix problem caused in decorrelation progress of reconstruction algorithm is solved by condition improved algorithm.Furthermore,the performance of each sub-algorithm and the BER perfonnance of overall algorithm are tested and analyzed by simulation and system level tests.(3)Based on the summary of existing research on CPM/PN signal,the common-used patterns of PN code added on CPM signal are collected in this paper.Also,the composition of power spectrum of CPM/PN signal with each pattern is derived and analyzed.Especially,the vague replacement and the subsequent miscalculation in the derivation of signal's power spectrum are corrected by reasonable replacement.Further,the derived results of different PN and CPM/PN signal are verified by simulation.Besides,the consulting value on reality application of this research is explained by two example:the spectrum constraint problem of applying CPM/PN signal in VLC and parameters selection of applying GMSK/PN signal in deep-space communication.