Along with the development of modern military and the technology is more and more closely, individual soldier system, which is considered, planned and designed from the three aspects of man, machine and environment, is a man-machine system as an important link of the information battlefield. As an important part of individual soldier system, the basic requirements of portable communication system for individual soldier is of high security, high reliability, high stability, and low power consumption. Transmitreference mode is used in differential chaos shift keying(DCSK) system. Both reference signals and information-bearing signals are sent to the receiver. The target information can be obtained without any channel estimation. Thus, the DCSK system not only has the properties of chaotic signal, such as good auto-correlation and cross-correlation properties, wide-band property, noise-like property, and good security, but also has following advantages: low probability of intercept, anti-multipath interference ability, low bit error rate, simple system structure, easy to implement. It has a broad prospect and a significant research value in the portable communication system for individual soldier.In this work, in order to enhance the anti multipath interference of DCSK system, improve spectral efficiency and energy efficiency of DCSK system, and solve the problem of delay circuits, we deeply study DCSK system under the background for the transmission of video, voice, maps and other confidential information in the portable communication system for individual soldier. The main contributions in this work are given as follows.(1) We study the production of chaotic sequence for DCSK system. We analyze the six cell cellular neural network system and propose a selection algorithm for hyper chaotic system. We can obtain lots of hyper chaotic systems based on cellular neural network under the help of the proposed selection algorithm. In order to solve the problem that the performance of the chaotic sequences which are generated directly from the chaotic system is unstable, we propose a selection algorithm for chaotic sequence. After the selection based on the random properties, auto-correlation and cross-correlation, lots of chaotic sequences with good properties can be obtained, which could enhance the bit error rate(BER) performance and security. This part is the foundation for further study of DCSK system.(2) We design DCSK system based on multiple-input and single-output(MISO). In order to solve the problem that the maximum available rate is limited by the modulation mode, we borrow the idea from Walsh-DCSK system, which belongs to SIMO-DCSK system, and then propose a new signal superposition multiplexing algorithm based on group decoding, which can enhance the maximum available rate. In order to meet the needs of video transmission demand in portable communication system for individual soldier, inspired by the structure of space time block code(STBC) in two-user interference channel and X channel, and by the idea of analog STBC-DCSK system, we design MISO-DCSK system that has the unequal error protection property. In order to further enhance the BER performance of MISO-DCSK system, we design enhanced MISO-DCSK system. In MISO-DCSK system, each bit has different BER performance in each STBC time slot, which can be seen as a kind of unequal error protection property. This feature is consistent with the nesting property of video sequences. Thus, the designed enhanced MISO-DCSK system is suitable for video transmission in portable communication system for individual soldier.(3) We study the DCSK system based on orthogonal frequency division multiplexing(OFDM). In order to solve the problem that the receiver of group decoding algorithm in OFDM has high decoding complexity, we propose a hybrid decoding algorithm, which switches between group decoding algorithm and minimum mean square error algorithm.The proposed hybrid decoding algorithm can decrease the decoding complexity. In order to meet the needs of digital information transmission demand in portable communication system for individual soldier, and solve the problem that DCSK system has low spectrum efficiency, the delay circuits are needed at the receiver, and the system is unable to deal with deep fading, we design OFDM-DCSK system. We analysis the energy efficiency and BER performance under Nakagami-m channels for OFDM-DCSK system.(4) We study the DCSK system based on generalized frequency division multiplexing(GFDM). In order to solve the problem that OFDM system has high out-of-band emission, we study GFDM system. To solve the problem that GFDM system has selfinterference between the subcarriers, we propose Gold-GFDM system, which can enhance the robust of GFDM system. In order to meet the needs of digital information transmission demand in portable communication system for individual soldier, and solve the problem that the channel estimation is difficult for GFDM system, and the problem of high out-of-band emission for OFDM-DCSK system, we design GFDM-DCSK system.Considering the properties of GFDM system, two GFDM-DCSK system are designed. We analyze the BER performance under AWGN channels. Compared with OFDM-DCSK,GFDM-DCSK system decrease out of band emission with the expense of perfect orthogonality of subcarriers. |