The Improvement In Communication And Location Multiplex System And Design Of Its Transmitter

With the complication of the electromagnetic environment in wireless communication and the enhanced performance requirement in the communication system, the traditional single code communication and location multiplex system is loosing its capacity to fulfill the practical needs. In view of the inconsistent between the technical parameters and the period of the PN code, an improved communication and location multiplex system based on the technique of tamed spread-spectrum is put forward in this paper.A key technology of the improved complex system is the select of the concatenated sequence, which will determine the design of the code acquisition and TDOA estimation methods in the receiver, and finally has an effect on the range of telemeter, the precision of telemeter and the performance of the communication. In this improved complex system, a novel kind of concatenated sequence is adopted, using the modified complete complementary series as its inner sequence. The theory of complete complementary series is studied here. And to reduce the multi-path and multi-access interferences in the spread spectrum system, the modification algorithm of the complete complementary series is presented in this paper. In accordance with the novel concatenated sequence, the two-stage fast code acquisition scheme and TDOA estimation methods in the receiver has been discussed in detail.At last, based on the technique of DSP, FPGA, and DDS, a hardware scheme to realize the transmitter platform in an improved multiplex system is proposed in the last part of this paper, providing a universal, digitized and expandable platform for further research in the communication and location multiplex system.