The Study About A Three-Dimensional Polarization Amplitude Modulation Method And Constellation Mapping

The two key issues of modern communications are how to reduce the error rate of the communication system and how to improve the transmission rate communication systems. In order to solve the above problems, researchers have proposed many new three-dimensional modulations, polarization Quadrature amplitude modulation (PQAM) that is one of them. This modulation scheme may be regarded as a combination of PAM and QAM. Comparing with the traditional one-dimensional or two-dimensional modulation, the PQAM can improve the communication efficiency and reduce the symbol error rate (SER) of the system. But its SER was affected by distributive relations between the order 2M of the Pulse Amplitude Modulation (PAM) and the order 2N of the Quadrature Amplitude Modulation (QAM). In order to obtain the minimum SER, a specific distribution about M, N was proposed in this paper, and this distribution proved to be the best method of distribution.In order to have a constellation which can match with PQAM, we study the relationship between structure of constellation and the dimension, SER, as well as the average power of constellation and designed three different structures constellation depending on the order of PQAM. In addition, in order to analyze the SER performance of each constellation proposed, we also analyzed the probability of correct decision of various types of constellation points in the constellation, and then use the probability of correct decision represented SER of each constellation. In order to compared the BER of the constellations and the BER in the PQAM system conveniently, we also calculated the average power Es about every constellations, then calculated for signal to noise ratio (Es/NO) of each constellation in Additive White Gaussian Noise channel, and make the Es/NO as a variable during simulation.Finally, in order to show the relationship between the PQAM BER and the distribution about the PAM and QAM concisely, we simulated the BER of PQAM system under various distribution about M, N situation, and the results also proved that the distribution proposed in this paper is optimal. Furthermore, in order to better determine the error performance of each constellation, the article also compared the SER of the constellation with the smallest BER of the PQAM when their order is the same, and the results show that the SER of the constellation design in the paper is quite close to the SER of the PQAM system.