Spatial Correlation - Impact On Performance

Impact On Performance

The spatial correlation (i.e., the eigenvalue spread in or ) has an impact on the performance of a multiantenna system. This impact can be analyzed mathematically by majorization of vectors with eigenvalues.

In information theory, the ergodic channel capacity represents the amount of information that can be transmitted reliably. Intuitively, the channel capacity is always degraded by receive-side spatial correlation as it decreases the number of (strong) spatial directions that the signal is received from. This makes it harder to perform diversity combining.

The impact of transmit-side spatial correlation depends on the channel knowledge. If the transmitter is perfectly informed or is uninformed, then the more spatial correlation there is the less the channel capacity. However, if the transmitter has statistical knowledge (i.e., knows and ) it is the other way around – spatial correlation improves the channel capacity since the dominating effect is that the channel uncertainty decreases.

The ergodic channel capacity measures the theoretical performance, but similar results have been proved for more practical performance measures as the error rate.

Read more about this topic:  Spatial Correlation

Famous quotes containing the words impact on, impact and/or performance:

    Too many existing classrooms for young children have this overriding goal: To get the children ready for first grade. This goal is unworthy. It is hurtful. This goal has had the most distorting impact on five-year-olds. It causes kindergartens to be merely the handmaidens of first grade.... Kindergarten teachers cannot look at their own children and plan for their present needs as five-year-olds.
    James L. Hymes, Jr. (20th century)

    Conquest is the missionary of valour, and the hard impact of military virtues beats meanness out of the world.
    Walter Bagehot (1826–1877)

    True balance requires assigning realistic performance expectations to each of our roles. True balance requires us to acknowledge that our performance in some areas is more important than in others. True balance demands that we determine what accomplishments give us honest satisfaction as well as what failures cause us intolerable grief.
    Melinda M. Marshall (20th century)