本文選題：無線組播 + 雙時隙��； 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：無線組播技術(shù)可以在同一頻段向不同用戶同時發(fā)送相同數(shù)據(jù),從而大大提高頻譜效率并增加系統(tǒng)容量。近年來,對于無線組播及其相關(guān)技術(shù)的研究越發(fā)熱門。尤其是在狀態(tài)控制、時鐘同步以及諸如IPTV、視頻會議這些新興業(yè)務(wù)中,無線組播的高效可靠為它們提供了強大的技術(shù)支持。由于傳統(tǒng)組播時通常采用信道狀態(tài)信息(Channel State Information,CSI)最差用戶的可達速率進行數(shù)據(jù)傳輸,這雖然可以保證組播成功率,但是傳輸速率較低,尤其是隨著用戶數(shù)量的增加,組播速率可能趨于極低值,組播系統(tǒng)的容量也相應(yīng)急劇降低;而另一種方法則是采用預(yù)設(shè)的固定速率進行傳輸,但可能導(dǎo)致中斷概率較高,不能滿足系統(tǒng)的成功率要求,導(dǎo)致整個組播無法獲得預(yù)期的容量增益。采用協(xié)作通信的雙時隙組播技術(shù)利用重傳轉(zhuǎn)發(fā)可以很好地克服上述缺點。該方法利用協(xié)作通信與數(shù)據(jù)重傳技術(shù),通過空間分集與時間分集獲得復(fù)用增益,在提高系統(tǒng)容量的同時兼顧了用戶公平性。然而,已有的雙時隙協(xié)作組播大部分都是建立在時隙長度固定或者發(fā)射功率固定的基礎(chǔ)上,隨著綠色通信的日漸普及,以及無線組播系統(tǒng)對續(xù)航能力的要求的提高,提高無線組播通信的能量效率的相關(guān)研究也越發(fā)重要,中繼功率可變與時隙可變的組播方案研究在這方面有著重要意義。本文從協(xié)作組播模型出發(fā),針對基于終端到終端(Device-to-Device,D2D)技術(shù)的雙時隙組播模型下的資源分配問題,展開了以下研究工作:首先,分析了協(xié)作組播技術(shù)中的雙時隙重傳組播系統(tǒng)模型,總結(jié)歸納了典型的雙時隙協(xié)作組播方法,并給出了簡單的性能分析與比較。其次,在中繼功率動態(tài)可變的基礎(chǔ)上,提出了一種基于信道增益的功率分配方案。首先在雙時隙組播的基礎(chǔ)上構(gòu)建了功率可變的中繼模型,然后通過半定松弛進行約束放縮,轉(zhuǎn)化為凸優(yōu)化問題,進而求解得到了相應(yīng)的功率分配方案。最后,從降低接收復(fù)雜度的角度,對用戶接收信號的合并方式進行了簡化改進,并研究了合并路數(shù)對性能的影響。再次,從時隙可變的角度出發(fā),研究了雙時隙組播模型下的時隙因素對于無線組播能效的影響。將時隙因素與功率控制結(jié)合起來,研究了不同時隙分配方案下組播系統(tǒng)的能量效率,針對集中式系統(tǒng)與分布式場景下的組播系統(tǒng)分別進行了分析與仿真,結(jié)果顯示與傳統(tǒng)固定時隙方案相比獲得了顯著的性能提升。
[Abstract]:Wireless multicast technology can simultaneously transmit the same data to different users in the same frequency band, thus greatly improving the spectral efficiency and increasing the system capacity. In recent years, the research on wireless multicast and its related technologies has become more and more popular. Especially in state control, clock synchronization and emerging services such as IPTV and video conferencing, the high efficiency and reliability of wireless multicast provide powerful technical support for them. In traditional multicast, the data transmission rate of the worst users of Channel State Information (CSI) is usually used for data transmission, which can guarantee the success rate of multicast, but the transmission rate is low, especially with the increase of the number of users. The multicast rate may tend to be extremely low and the capacity of the multicast system will decrease rapidly. Another method is to adopt a fixed rate of transmission, but it may lead to a high probability of interruption, which can not meet the requirements of the system's success rate. As a result, the entire multicast can not achieve the desired capacity gain. The double time slot multicast technology for cooperative communication can overcome these shortcomings well by retransmission and forwarding. The method uses cooperative communication and data retransmission techniques to gain multiplexing gains through spatial diversity and time diversity, which improves system capacity and takes account of user fairness. However, most of the existing double time slot cooperative broadcasts are based on fixed slot length or transmission power. With the increasing popularity of green communication and the improvement of the requirement of the wireless multicast system, The research on improving the energy efficiency of wireless multicast communication is becoming more and more important. The research of multicast schemes with variable relay power and time slot is of great significance in this respect. Based on the cooperative group broadcasting model, this paper focuses on the resource allocation in the dual-slot multicast model based on the Device-to-device D2D technology. The following research works are carried out: firstly, the model of the dual-slot retransmission multicast system in the cooperative group broadcasting technology is analyzed. In this paper, the typical double time slot cooperative broadcasting methods are summarized, and simple performance analysis and comparison are given. Secondly, a power allocation scheme based on channel gain is proposed based on the dynamic variation of relay power. Firstly, a relay model with variable power is constructed on the basis of double time slot multicast, then the constraint scaling is done through semidefinite relaxation, which is transformed into a convex optimization problem, and the corresponding power allocation scheme is obtained. Finally, from the point of view of reducing the reception complexity, the merging mode of the received signals is simplified and improved, and the effect of the number of the merging paths on the performance is studied. Thirdly, from the point of view of time-slot variable, the effects of slot factors on wireless multicast energy efficiency under the dual-slot multicast model are studied. Combining slot factor with power control, the energy efficiency of multicast system under different slot allocation schemes is studied. The analysis and simulation of multicast system under centralized system and distributed scenario are carried out. The results show that compared with the traditional fixed time slot scheme, the performance is improved significantly.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN92

【相似文獻】

相關(guān)期刊論文 前10條

1 王莉;易本順;艾濱;;可控組播管理研究[J];武漢理工大學(xué)學(xué)報(交通科學(xué)與工程版);2007年05期

2 姜臘林;文澤龍;;差異化剪枝組播計費算法[J];長沙理工大學(xué)學(xué)報(自然科學(xué)版);2013年01期

3 杜t，

本文編號：2098477