power fading 中文意思是什麼
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As the application of rake receivers with multitaps is widely used in cellularcdma systems for exploiting path diversity, the closed - loop power control schemesshould make use of the multitap rake receivers for tracking the power variation dueto path loss, slow fading, and fast fading
同時，本文給出的自適應變步長閉環功率控制演算法利用rake接收機跟蹤通道的變化，與傳統的固定步長閉環功率控制相比獲得了較小的ebi0標準差。 -
Based on in - depth study on the mc - cdma system structure, we proposed a combined power and rate control scheme for wcdma over fading channels
在mc - cdma這種方案中，我們提出了功率控制優先於速率控制的演算法。 -
It consists of a powr compensation algorithm based on reverse channel prediction and closed - loop power control algorithm. computer simulation showed that the scheme could compensate the fast channel fading quite well
它由基於反向通道預測的功率補償演算法和常規閉環功率控制組合而成。計算機模擬結果表明，所提出的組合功率控制方案能夠很好地補償通道的快速衰落。 -
Neither american hard nor soft power is fading
美國的硬實力和軟實力都沒有變弱。 -
This paper mainly discusses the design principles and chief techniques of a digital accessing system for power - line communication net ( plcn ). the technology of low bit rate speech compression high - speed modem based on plcn adaptive equalization to the channel anti - jamming and anti - fading are applied in this system. so speech tele - control data and tele - protection signals can be transmitted high quality in the band - limited channel
該系統綜合應用了低比特率語音信號壓縮編碼技術、基於電力通信網的高速調制解調技術、信號傳輸的通道自適應均衡技術和抗干擾、抗衰減技術，可在帶限通道中高質量的傳輸語音、遠動數據和遠方保護等信號，具有較高的整體性能。 -
When transmitting signal is below 500 kbps, increasing the system power can reduce the bit error rate ( ber ) for the signal suffering only flat fading
當碼速率較低時（ 500kbps以下） ，信號受到平坦衰落，增大系統功率可以降低系統誤碼率。 -
But when the bit rate is above 1 mbps, the signal suffers frequency select fading, which causes the serious intersymbol interference ( isi ). increasing the system power can ’ t reduce the ber
但是當碼速率提高到1mbps以上時，信號受到頻率選擇性衰落，碼間干擾嚴重，增大系統功率也不能降低系統誤碼率。 -
In this scheme, power control is primary to the rate control. when the fading channel changes slowly, the transmit data rate will be kept on an appropriate level, and only the power control works to keep up with the channel fading and balance the sir. but when the channel quality is poor, the data rate will be switched down without sacrificing the ber ; otherwise, high data rate was selected
我們提出的方案根據反饋的sir動態改變數據的速率和功率，其中功率控制優先於速率控制，當通道變化緩慢時，數據率保持在一個相對穩定的值上，調節發射功率來維持sir平衡；當功率調節無法彌補通道的衰落時，則通過調節速率來維持sir的平衡。 -
Combined with the adaptive modulation and coding technology, this algorithm reallocates the residual power by effectively utilizing the discrete modulation orders according to the different priorities of sub - channels under the limitation of quality of service over the block fading channel
在滿足服務質量要求的前提下充分利用星座圖尺寸的離散性，將殘余功率按照各子通道的不同優先級進行二次分配，並結合自適應調制編碼技術改善低信噪比時的系統吞吐量。 -
Secondly, we present a new transmit diversity scheme with adaptive power allocation in which two antennas are employed at the transmitter, and the effect of the channel estimation error on its performance is also analyzed. theoretical analysis and simulation results indicate that the new scheme has a considerable performance gain and is robust to the estimate bias of channel fading parameters
其次，提出了在雙天線發送分集中對不同天線的發送功率進行優化分配的技術方案，並分析了通道估計誤差對其性能的影響，理論分析和模擬結果表明：在alamouti雙天線發送分集中採用自適應優化功率分配，不僅提高了系統的性能，還可以提高其對通道估計誤差的魯棒性。 -
Space - time coding technology is based on multi - elements antenna array and has strong points of both time processing and space processing. it can satisfy the requirements of high data rate transmission in the future radio mobile system without the increase of the transmitting power and the spread of the frequency. and it can greatly improve the quality of communication services and system capacity under fading channels
空時編碼技術是一種利用多天線陣發送和接收的技術，該技術能很好地結合時間處理技術和空間處理技術的特點，能在不增大發射功率和不擴展頻帶的前提下滿足未來無線移動通信對高數據率傳輸的要求，從而全面提高衰落通道的通信質量和通信系統容量。 -
Because of the affection of noise and signal fading, in order to high data rate access and high quality, wireless communication need new technology to improve the link reliability and enhance the spectrum efficiency. mimo ( multiple input and multiple output ) can enhance the spectrum efficiency and increase channel capacity greatly, and reduce the multipath affection without spectrum band and power increasing. the 3th generation mobile communication wcdma is coming, with the purpose of putting mimo, stbc ( space time block coding ), space diversity into practice of wcdma systems, in order to lay the foundation of 3g toward 4g, this dissertation has done some research under this background
在發射機和接收機使用多個天線進行數據傳輸的多輸入多輸出（ mimo ）技術，可以在不增加帶寬和天線發送功率的條件下，成倍的提高頻譜利用率，提高系統的通道容量，還可以抗多徑干擾。第三代移動通信wcdma即將到來，為了將多天線技術（ mimo ） ，空間分集技術，空時編碼技術用到wcdma系統中去，為第三代移動通信向第四代移動通信系統平穩過渡奠定一定的基礎，需要做一些理論上的研究。 -
This article proposes the adaptive algorithm based on equal snr signal noise ratio, and applies it in adaptive ofdm system. in frequency selective fading channel, compared with the traditional ofdm system based on equal power allocation, the system outperforms in ber bit error ratio performance
提出了一種基於最小平均誤碼率的自適應預處理演算法，並將該演算法應用於自適應ofdm系統，在頻率選擇性衰落通道條件下，與等功率分配的ofdm系統相比，誤比特性能有了很大程度的提高。 -
The effect of fading margin to forward link transmit power and capacity of cdma2000 1x
前向鏈路發射功率和容量的影響 -
Space - time block codes ( stbc ) based on orthogonal design has attracts enough attentions in its applications in mimo - ofdm systems for its full diversity exploiting and low coding / decoding complexity. these applications include not only system performance improvement, but also reduction of the peak to average power ratio in mimo - ofdm systems. under these backgrounds, this paper first studies space - time block codes under the single carrier, flat fading situation, discusses the encoding / decoding principle and its performance under different channels. then, the author focused on the performance of space - time codes under time selective and frequency selective channels, uncovered the fundamental cause of how maximum doppler shift and power delay profile influences the performance of space - time codes through deduction and simulation
在上述背景下，本文以單載波，平坦衰落通道下的空時分組碼為切入點，深入分析了其編譯碼原理和在不同通道情況下的性能;以此為基礎，後文展開了對空時分組碼在多載波，時間選擇性和頻率選擇性衰落通道下的性能研究，通過理論推導和充分的模擬，揭示了空時/頻分組碼在時頻選擇性衰落通道中的性能變化的根本原因;在以上對多載波系統中空時分組碼的研究的過程中，作者發現了空時分組碼在降低系統峰平比方面應用的可行性，提出了一種降低峰平比的新方法。 -
It has many benefits due to its ultra - wideband nature which including the following : not sensitive to channel fading, low transmit power, extremely difficult to intercept, low complexity of transceiver structure, fine range resolution ( centimeter scale ) for location and so on this paper combines uwb technology and mobile ad hoc network technology, concerting the lasn project of national key laboratory of communication, researchs the baseband process cell of uwb communication transceivers on the base of arithmetic research and spot test
本文結合uwb技術和移動自組織網（ manet ，即mobileadhocnetwork ）技術，配合通信抗干擾技術國防重點實驗室uwb技術研究項目「 lasnproject 」的工作進展，在演算法研究和現場測試的基礎上，對uwb通信節點樣機的基帶處理單元進行設計研究。樣機結構包含三大模塊:天線、用分立器件形成的射頻電路、由fpga構建的基帶處理單元。 -
Future wireless communication systems trend to provide multi - services to mobile users. cdma technique is adopted by the 3rd generation mobile communication systems due to its flexibility in supporting multi - services. how to keep qos of heterogeneous services and utilize the scarce radio spectrum resources is challenging for 3rd generation mobile communication systems in this thesis we developed a radio resource allocation framework for wireless code division access ( cdma ) networks that support multi - class traffic with different data rates and bit error rate requirements. we proposed a new resource allocation scheme using joint adaptive power control and mmse multiuser receiver in multipath fading system
為移動用戶提供多種業務服務是未來無線通信網路的主要發展方向。由於cdma技術具有靈活支持多種業務的優點，因而被第三代移動通信系統所采納。如何在惡劣的無線傳播環境里以及用戶運動且相互干擾的情況下為為各類業務提供qos保證，同時充分利用珍貴的無線頻譜資源，是基於cdma技術的第三代蜂窩通信系統必須致力解決的問題。 -
This dissertation researches on wavelet theory applied to information transmission, including cdma spreading code design, waveform coding in digital modulation, over - saturated multi - access communication, diversity techniques for multi - path fading channels, and peak - to - average power ratio ( papr ) reducing methods for the wavelet packet modulation signals, etc.
本文以子波理論為工具，較深入地研究了通道傳輸方面的幾個問題，內容包括cdma擴展碼的設計、數字基帶波形成形技術、過飽和多址通信、克服衰落的分集技術和減小子波包調制信號的峰值功率/平均功率比值的方法等。
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