公开(公告)号：US20050265465A1

公开(公告)日：2005-12-01

申请号：US10857417

申请日：2004-05-27

申请人： Srinath Hosur ,  Jaiganesh Balakrishnan ,  Muhammed Ikram ,  Manish Goel ,  Michael Polley

发明人： Srinath Hosur ,  Jaiganesh Balakrishnan ,  Muhammed Ikram ,  Manish Goel ,  Michael Polley

IPC分类号： H03D1/00 ,  H04B7/02 ,  H04B7/10 ,  H04L25/02 ,  H04L25/06 ,  H04L27/06 ,  H04L27/26

CPC分类号： H04L27/2647 ,  H04L25/0204 ,  H04L25/067

摘要： In MIMO wireless communications employing LMMSE receiver, the symbols transmitted through a transmit antenna are estimated at the receiver in the presence of interference consisting of two main components: one due to the additive noise and the other due to (interfering) symbols transmitted via the remaining antennas. This has been shown to hamper the performance of a communication system resulting in incorrect symbol decisions, particularly at low SNR. IMMSE has been devised as a solution to cope with this problem; In IMMSE processing, the symbols sent via each transmit antenna are decoded iteratively. In each stage of processing, the received signal is updated by removing the contribution of symbols detected in the previous iterations. In principle, this reduces the additive interference in which the desired symbols are embedded in. Therefore, the interference level should reduce monotonically as one goes down in processing order. In a noisy environment, however, any incorrect decision made on a symbol in an iteration leaves its contribution in the updated received signal available for processing in the following iterations. Fortunately, if the level of interference is estimated and the soft bits are scaled appropriately by the estimated interference power, the performance of IMMSE receiver can be greatly improved. Preferred embodiments estimate the interference by computing the probability of error in decoding the symbols of the previous stage(s). The computation of decision error probability depends on the constellation size of transmitted symbols and introduces very little processing overhead.

摘要翻译： 在采用LMMSE接收机的MIMO无线通信中，在存在由两个主要部分组成的干扰的接收机处估计通过发射天线发射的符号：一个由于加性噪声而导致的，另一个是由于通过剩余的 天线。 已经显示出妨碍通信系统的性能，导致不正确的符号决定，特别是在低SNR下。 IMMSE已被设计为解决这个问题的办法; 在IMMSE处理中，经由每个发送天线发送的符号被迭代地解码。 在每个处理阶段，通过去除在先前迭代中检测到的符号的贡献来更新接收到的信号。 原则上，这降低了嵌入期望符号的附加干扰。因此，干扰电平在处理顺序下降时单调减少。 然而，在嘈杂的环境中，在迭代中对符号做出的任何不正确的决定使其在更新的接收信号中的贡献可用于在以下迭代中进行处理。 幸运的是，如果估计干扰水平，并通过估计的干扰功率适当地缩放软比特，则可以大大提高IMMSE接收机的性能。 优选实施例通过计算解码前一级的符号的误差概率来估计干扰。 决策误差概率的计算取决于传输符号的星座大小，并引入很少的处理开销。