Research On The Sample-interweave Cwtdm Transmission System And Its Application

Continuous Wave Time Division Multiplex (CWTDM) is an invention patent of ours. It can solve the problem of reliably transmitting multiple continuous signals in a continuous channel by means of time division multiplexing. This technique can find some important applications in the satellite communications based on onboard FDMA-CWTDM conversion and in multiple data transmission over wireless fading channels.There are two methods to realize CWTDM, i.e. sub-frame overlap-adding method and sample-interweave method. This thesis mainly deals with the structure and design of the sample-interweave CWTDM communication system, with an emphasis on the key techniques of the wireless channel equalization and high precise frame synchronization. Besides, a wireless transmitting/receiving system for multi-lead ECG (Electrocardiograph) signals is developed, to demonstrate an application of the sample-interweave CWTDM. The author's main contributions are as follows:1．Basing on research of the principle and key techniques of the sample-interweave CWTDM, the thesis proposes a scheme of CWTDM communication system, including the structure of its transmitter, receiver and the related modules, and has completed the simulations in MATLAB to verify the function of the system.2．About channel equalization in the CWTDM system, a specific pilot sequence is employed to estimate the channel to realize adaptive channel equalization. Moreover, a modified LMS algorithm is proposed for the adaptive linear equalizer, which can remarkably reduce the hardware resources.3．Through researching in depth on the typical channel models in mobile communications, the previous channel equalizer is validated and tested under such environments. The simulation results demonstrate that the adaptive equalizer is effective in a slow fading channel.4．A wireless transmitting and receiving system for multi-lead ECG signals is designed based on the sample-interweave CWTDM. The author succeeds in developing its PCB to realize the collection, processing and transmission of the ECG signals, and completing the software design at the receiver. The basic functions of the system have been proved by some experiments.