Multiple input multiple output (MIMO) systems are widely used in many practical wireless communications system [1 4].
The following analysis intentionally ignores many practical aspects of a wireless communications system, including physical layer waveform design, gains, filters, analog/digital conversion, and channel effects.
For many practical applications, such as satellite communications [9], an antenna array is required to possess the beamforming capability that receives more than one SOI with specified gain constraints while suppressing all.
In many practical situations, especially for mobile cooperative communications, the direct link may not be ignored.
In many practical applications such as seismic surveying, detection, system identification, sonar, communications, speech, and medical instrumentation, the signal analysts are faced with the task of processing signals whose spectral characteristics are time-dependent [1] and [2].
During the past 25 years, a wealth of algorithms have been proposed and ICA-based methods are now extensively and successfully applied to solve many practical real-life problems such as biomedical signal analysis and processing, wireless communications, data mining, speech enhancement, image recognition, etc. (see [3] for details).
But that leaves many practical questions unanswered.
There are so many practical demands that men should support.
But he has yet to offer many practical details.
And there are many practical considerations.
