Research On Power Division Multiple Access Technology Based On WARP Platform

With the rapid development of wireless communication science and technology in today's society and the increasing demand for high-quality instant wireless communication,traditional multiple access technology can no longer meet the current signal transmission task.Therefore,power division multiple access(PDMA)technology is proposed in this paper.This technology multiplexes the information channel from the power point of view,and allocates the address reasonably,so as to save the information channel resources.Aiming at the construction and verification of the actual scene of communication system based on power division multiple access technology,through the transmission verification of software radio WARP platform,the signal is superimposed according to the principle of power distribution,and the channel is reused to verify the final demodulation results.The feasibility of this technology is analyzed by the analysis of constellation points.The main contents of the paper are as follows:1.The feasibility of two signals with different power in base band stacking,single antenna receiving and dispatching and signal recovery process is verified,and the single-channel transceiver transmission function is realized.Through the transmission and exploration based on WARP platform,the constellation map of signal mapping is analyzed and the bit error rate is observed,which verifies the feasibility of the technology based on single-channel receiving and dispatching system.The experimental results show that the position of the constellation points mapped by the demodulated signal is reasonable,and the coincidence degree between the constellation points mapped by the signal at the transmitter and the signal at the transmitter is high.The coincidence rate between the demodulated data and the pseudo-random sequence at the originator is 100%.In this system,the influence of the control factor gamma of signal power on the transmission quality of the system is investigated.2.The feasibility of two different power signals superimposed on the base band and transmitted by a single antenna is verified.The single and double transmit function of the system is realized.The two-way antenna at the receiving node of the WARP platform receives the base band superposition signal transmitted by the sender at the same time and demodulates the two-way signal before superposition.The feasibility of the system is verified by exploring the constellation diagram and observing the bit error rate.The position comparison of the constellation points mapped by the two-way signal received by the two-way antenna demodulation is carried out.The constellation points mapped by different receivers are better than the two-way signal from the originator.The coincidence rate between the obtained data and the pseudo-random sequence of the origin is 100%.Signals of different power levels are sent by a single antenna after being superimposed on the baseband,and the double-channel antenna at the receiving end can be demodulated to obtain the corresponding double-channel signals.3.Two signals with different power are superimposed in the frequency band and the receiver receives the superimposed signals and verifies the feasibility of recovering each signal.Therefore,The system has realized the double sending and receiving functions.In the WARP platform,the constellation map of the two-way signal mapping after demodulation is analyzed,and the rotation reason of the constellation point of the one-way signal mapping with less power is explored.After that,the feasibility of the system is simulated and verified in MATLAB.By demodulating and separating the superimposed signals at the receiving end,the signal with higher power gets good constellation mapping,while the signal with lower power rotates the constellation points.The reason is that the correction of phase noise in the inverse process is not complete enough after the demodulation of high-power signal.Improvements are needed in pilot Settings.