发射端分集、编码和调制结合空时格码，可以有效地提高信号在无线衰落信道中传输的有效性和可靠性；
Space-time trellis code combining space diversity with code and modulation, can improve efficiency and reliability of communication system in wireless channel efficiently.
其中主要为无线衰落信道中的多径传播和散射引起的信号衰落，以及大的多径时延而引起的符号间干扰。
The problems mainly exhibit to be multi-path propagation in the wireless fading channel, signal fading caused by the scattering and Inter-Symbol Interference caused by the long multi-path time delay.
在无线衰落信道环境中，协作中继是一种增加额外分集增益的有效方法，而网络编码可以用来提高网络吞吐量。
In the wireless fading channel environment, cooperative relaying is an effective way to increase additional diversity gain, and network coding can be used to increase network throughput.
空时编码采用多发送天线设计信道编码，联合考虑分集、编码与调制，从而提高信号在无线衰落信道中传输的可靠性。
The design of channel codes for improving the reliability of communications over fading channel using multiple transmit antennas is considered.
另外在未来宽带MIMO无线通信系统中，通常面临频率选择性衰落信道，传统高性能均衡器就会变得异常复杂。
In addition, there will be frequency selective fading in the future broadband MIMO wireless communication systems, and the traditional high-performance equalizer will become extremely complicated.
第二章分析了无线信道的多径效应和小尺度衰落效应。
The second chapter of this paper analyzes the multipath effects and fading effects of wireless channel.
然后讨论了无线移动通信的传播环境，得到时变衰落信道的特点。
Then it analyzes the wireless mobile communication propagation environment and gets the characters of timing varying fading channel.
本文研究多径衰落信号的多重分形性质，分析并指出了信号多重分形维数是描述无线信道传播特性的重要参数；
Fractal characteristic of multipath fading signal is studied in the paper which shows that multifractal dimension is a key parameter for describing the signal propagation in wireless channels.
无线环境中存在多径衰落、多谱勒频移和信道快速时变等许多不利因素。
There are lots of disadvantages in wireless environment, such as multi-paths fading, Doppler frequency shift and fast time varying of channel.
由多径色散及多普勒频移造成的频率—时间选择性衰落是城市移动无线信道的一个重要特性。
The frequency time selective fading resulted from multipath dispersion and Doppler frequency shift is an important characteristic of urban mobile radio channel.
仿真结果表明，在慢衰落无线信道图像传输中，系统能获得满意的图像传输质量和很高的频谱利用率。
Simulation results show that the system can get satisfactory image communication performance in the very high spectral efficiency situation over the flat fading channel.
多天线空间分集技术是抵抗无线信道衰落的有效手段。
It is well accepted that spatial, or multiple-antenna, diversity is an efficient technique to combat the negative effects of channel fading in wireless networks.
对于无线移动通信系统来说，面临着系统带宽效率和多径衰落信道等诸多问题的挑战。
The system bandwidth efficiency and the dispersive of wireless channel are the big challenges for the wireless mobile communication system.
基于分级调制的中继协作技术可以很好地利用无线信道的广播特性和中继节点的位置优势来对抗信道衰落。
Cooperation with hierarchical modulation can employ broadcasting characteristics of wireless channel and location advantage of relay node to confront fading.
本文第一章绪论首先分析了无线信道的特性，介绍了小尺度衰落模型，多径衰落模型以及WSSUS信道模型。
The first chapter introduced the characteristics of the wireless channel, the small-scale fading model, multi-path fading model and WSSUS channel model.
在宽带无线数字通信系统中，影响信息高速传输的最主要的一类干扰是由信道的多径效应所引起的频率选择性衰落。
The bandwidth efficiency and ability to combat the effects of frequency selective channels are critical issues in the design of wideband wireless digital communications system.
在此基础上提出了一种新的无线信道模型；结合分形插值方法，对多径衰落信号的重构进行了研究。
Then a novel channel model is proposed and fractal interpolation is applied to reconstruct the signals.
数字通信系统中多径衰落的无线信道环境通常会使接收信号受到严重的码间干扰。
The received signal is often corrupted badly by inter-symbol interference in the multipath fa- ding wireless channel circumstance.
另外，信号经过无线信道传输时会有衰落，如不补偿信道影响的话将会无法正确解调信号。
Also when transmitted through wireless channels, signals are attenuated, which results that signals can not be demodulated correctly.
根据北京地区移动通信无线电传播规律，在信号快衰落幅度服从m衰落的基础上，给出了M衰落波形信道的计算机仿真模型。
Based on the propagation regularity of land mobile communication in Beijing, this paper gives the computer simulation model of M-distribution fading wave channel.
日益增长的无线业务需求要求提高衰落信道上无线通信的频谱利用率。
The growing demand for wireless services has created the need for improving the spectral efficiency of wireless communications over fading channels.
在未来的宽带无线通信系统中，存在着两个严峻的挑战：无线信道的多径衰落和频谱效率。
There are two serious challenges in the future broadband wireless communication systems: multi-path fading in the wireless channel and spectral efficiency.
多载波调制技术是一种并行数据处理方式，有效地对抗多径衰落，可以提高无线带限信道的数据传输速率。
Multicarrier modulation is a form of parallel data transmission, which is efficient to reduce the detrimental effects of multipath fading.
TTIB（透明带内导音）及FFSR（前馈信号再生）技术是一种可抗无线信道中多径时延及多谱勒频移引起的信号衰落的技术。
Transparent tone-in-band(TTIB) and feedforward signal regeneration(FFSR) is a technology to combat the effects of multipath propagation delay and doppler effect in wireless channels.
正交频分复用(OFDM)技术能够有效的对抗无线信道的频率选择性衰落，成为无线通信领域的另一个研究热点。
Orthogonal frequency division multiplexing (OFDM) can effectively combat the multipath fading of wireless channels and has become another hot point in the area of wireless communications.
在无线通信系统中，由于多径效应常常引起信道衰落，直接结果是码间干扰非常严重。
In wireless communication system, Inter-symbol Interference is serious and signal is distorted extremely because of fading channel resulted in by the effect of multipath.
在无线移动通信系统中，信道的衰落会降低信号传输的可靠性。
In wireless communication system, channel fading can decrease the reliability of communications.
但作为一个无线通信系统，所传输的信号必然受到无线信道的多径快衰落影响从而降低信号的接收质量。
However, as a wireless communication system, the signal transmitted on the wireless channel should be affected by multipath fast fading and the received quality of the signal will be lowered.
通过实践应用证明，此衰落模型在实际网络的节点部署和节点定位中的作用优于其他无线信道衰落模型。
This paper presented a model about the channel fading in the indoor physical environment of the wireless sensor networks.
通过实践应用证明，此衰落模型在实际网络的节点部署和节点定位中的作用优于其他无线信道衰落模型。
This paper presented a model about the channel fading in the indoor physical environment of the wireless sensor networks.
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