ITR/SI(CISE): MIMO Processing and Space-time Coding with Interference

ITR Small ProposalCCR-0112501Blum，Rick用于形成多输入多输出（MIMO）信道的发射和接收天线阵列在无同信道干扰的隔离单链路通信中显示出巨大的潜力。最近的研究表明，在使用相同数量的发射和接收天线的情况下，容量与发射天线的数量成线性比例。 这一结果引起了研究人员的极大兴趣。 虽然这些MIMO系统在没有同信道干扰的情况下已经得到了广泛的研究，但同信道干扰的情况却很少受到关注。此外，新的仿真结果表明，同信道干扰可以显着降低整体容量时，MIMO信道在蜂窝系统中使用相同的方式，其中它们被用于情况下没有干扰。 研究人员研究了MIMO系统的干扰特性，以开发使用MIMO的新方法，使传输方案适应干扰环境。这些新方法称为流控制算法，传输几个不同的流，每个流使用不同的传输权重向量。 可以发送的流的最大数量等于发送和接收天线的数量中的最小值。 所选择的流的确切数量取决于干扰环境的当前感测状态。 初步结果表明，显着的性能增益，可以实现这种方式。 利用发展良好的功率控制理论，正在开发分布式算法来控制在具有同信道干扰的蜂窝系统中采用的流的数量。 空时编码的使用也正在结合流控制进行研究。 无线信道的频率选择性衰落，各种相关结构，和其他实际退化正在研究。

ITR Small ProposalCCR-0112501Blum, RickTransmit and receive antenna arrays used to form multiple-input multiple-output (MIMO) channels have shown great potential in isolated, single link communications without cochannel interference.Provided the same number of transmit and receive antennas are used, recent research has shown that capacity scales linearly with the number of transmit antennas. This result has created an incredibleflurry of interest among researchers. While these MIMO systems have received extensive study for cases without cochannel interference, cases with cochannel interference have received much lessattention. Further, new simulation results indicate that cochannel interference can significantly degrade the overall capacity when MIMO channels are used in a cellular system in the same manner in whichthey are used for cases without interference. The investigators study the properties of MIMO systems withinterference to develop new methods of using MIMO which adapt the transmission scheme to the interference environment. These new methods, called stream control algorithms, transmit several different streams, each one using a different transmit weight vector. The maximum number of streams that can be transmitted is equal to the minimum of the number of transmit and receive antennas. The exact number of streams chosen depends on the current sensed state of the interference environment. Preliminary results indicate that significant performance gains can be achieved in this manner. Using the well developed theory of power control, distributed algorithms are being developed to control the number of streams employed in a cellular system with cochannel interference. The use of space-time coding is also being studied in conjunction with stream control. Wireless channels with frequency selective fading, various correlation structures, and other practical degradations are being studied.