A non-coherent blind detection method based on the generalized negative entropy mechanism for chaotic ultra-wideband system is proposed in this paper. In the case without knowing the transmission channel information, the chaotic impulse signals can be detected. The proposed method can overcome the practical application problem existing in the direct chaotic communication (DCC) scheme for impulse radio ultra-wideband (IR-UWB) communication system. Also, this method can overcome the complicated and unknown multipath channel effect. Analysis of simulation results show that the proposed approach has a good separating and detection performance in the case without knowing the channel information. A new way for the noncoherent blind detection of chaotic UWB system under non-ideal unknown channel. is established.

According to the electromagnetic theory of ultra-wideband radio positioning, an ultra-wideband spatial spectrum algorithm was proposed. The time-reversal operator expressed as multi-frequency by using the frequency band segmentation of ultra-wideband signal source was obtained combining with multiple signal classification (MUSIC) algorithm. The simulation results effectively prove that the utilized method has better positioning and imaging capability.

The performances of a PCTH-based communication UWB system with diversiform modulation schemes are compared on the classic AWGN channel propagation and the realistic IEEE-UWB channel model. By employing different versions of modulation at the transmitters, the performances of an optimal receiver and a Rake receiver with various combining schemes are studied in this paper. The numerical results for several compared cases illustrate the tradeoff between transmitter diversity and receiver complexity. It is shown that the actual performance of the PAM-PCTH scheme can be better in both kinds of channel propagation. We also find that the PCTH-based UWB system with the Rake receiver has better performance than the conventional proposal for overcoming the multipath propagation effects in the UWB indoor environment.

A novel method to extract multiple input and multiple output (MIMO) chaotic signals was proposed using the blind neural algorithm after transmitting in nonideal channel. The MIMO scheme with different chaotic signal generators was presented. In order to separate the chaotic source signals only by using the sensor signals at receivers, a blind neural extraction algorithm based on higher-order statistic (HOS) technique was used to recover the primary chaotic signals. Simulation results show that the proposed approach has good performance in separating the primary chaotic signals even under nonideal channel.

The performances of pseudo-chaotic communication time-hopping UWB system with efficient modulation schemes are compared on the classic AWGN channel propagation and the realistic IEEE-UWB channel model. By employing different versions of modulation at the transmitters, the performances of an optimal receiver and a Rake receiver with various combining schemes are studied in this paper. The numerical results for several compared cases illustrate the tradeoff between transmitter diversity and receiver complexity. It is shown that the actual performance of the PAM-PCTH scheme can be better in both kinds of channel propagation. We also find that the PCTH-based UWB system with the Rake receiver has better performance than the conventional proposal for overcoming the multipath propagation effects in the UWB indoor environment.

A novel method to extract multiple input and multiple output (MIMO) chaotic signals using the blind extraction algorithm after transmitting in nonideal channel is proposed in this paper. In order to solve the multipath problem in the direct chaotic communication ultra wideband (UWB) system, a blind extraction algorithm based on higher-order statistic (HOS) technique to recover the primary chaotic signals is introduced. Simulation results show that the proposed approach has good performance in separating the primary chaotic signals even under nonideal multipath channel.