Communication over MIMO X channels: Interference alignment, decomposition, and performance analysis
Communication over MIMO X channels: Interference alignment, decomposition, and performance analysis
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DOI：
10.1109/tit.2008.926460
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发表时间：
2008-08-01
影响因子：
2.5
通讯作者：
Khandani, Amir Keyvan
中科院分区：
文献类型：
--
作者：
Maddah-Ali, Mohammad Ali;Motahari, Abolfazl Seyed;Khandani, Amir Keyvan
在具有两个发射机和两个接收机的多天线系统中，研究了被称为X信道的数据通信的场景，其中每个接收机从两个发射机接收数据。在这种情况下，假设每个发射机都不知道其他发射机的数据（非合作情况）。该系统可以被认为是两个广播信道（从发射机的角度来看）和两个多址信道（从接收机的角度来看）的组合。利用这两个角度，两个信令方案，这样的情况下开发。在这些方案中，在发射机和接收机处采用一些线性滤波器，这些线性滤波器将系统分解成两个互不干扰的多天线广播子信道或两个互不干扰的多天线多址子信道。滤波器设计的主要目标是利用信道矩阵的结构来实现最高的复用增益（MG）。结果表明，建议的非合作信令方案优于其他已知的非合作方案的可实现的MG。特别是，它表明，在某些特定的情况下，所实现的MG是相同的MG的系统，如果提供充分的合作，无论是在发射机之间或接收机之间。在第二部分的文件，它表明，通过使用混合设计方案，而不是分解方案，并考虑到干扰项的统计特性，可以改善系统的功率偏移。功率偏移表示和速率与以分贝为单位的总功率的曲线中的水平移位。
In a multiple-antenna system with two transmitters and two receivers, a scenario of data communication, known as the X channel, is studied in which each receiver receives data from both transmitters. In this scenario, it is assumed that each transmitter is unaware of the other transmitter's data (noncooperative scenario). This system can be considered as a combination of two broadcast channels (from the transmitters' points of view) and two multiple-access channels (from the receivers' points of view). Taking advantage of both perspectives, two signaling schemes for such a scenario are developed. In these schemes, some linear filters are employed at the transmitters and at the receivers which decompose the system into either two noninterfering multiple-antenna broadcast subchannels or two noninterfering multiple-antenna multiple-access subchannels. The main objective,in, the design of the filters is to exploit the structure of the channel matrices to achieve the highest multiplexing gain (MG). It is shown that the proposed noncooperative signaling schemes outperform other known noncooperative schemes in terms of the achievable MG. In particular, it is shown that in some specific cases, the achieved MG is the same as the MG of the system if full cooperation is provided either between the transmitters or between the receivers.In the second part of the paper, it is shown that by using mixed design schemes, rather than decomposition schemes, and taking the statistical properties of the interference terms into account, the power offset of the system can be improved. The power offset represents the horizontal shift in the curve of the sum-rate versus the total power in decibels.