Experimental Characterization of the Outdoor MIMO Wireless Channel Temporal Variation

Abstract

Time-variant multiple-input multiple-output (MIMO) channels are measured in an outdoor campus environment at 2.45 GHz with directional patch arrays and omnidirectional monopole arrays. A number of useful metrics are proposed for quantifying time variation in MIMO channels: eigenvalue level crossing rate, eigenvector angular deviation, and capacity loss for delayed transmit and receive channel state information (CSI). Measurements in four different environments confirm the strong correlation between angular spread of multipath and MIMO channel time variability. The rate of time variation is also strongly influenced by the type of array, indicating that directional elements may be advantageous for highly mobile environments. The proposed metrics indicate that although the physical communication layer may need to update CSI several times per wavelength, the required rate of adaptation in transmit rate, modulation, and power allocation is much less severe.

Efficient wireless broadband communications for rural Australia

“…Wallace and Jensen conducted a significant research work [4], [24], [25] on time variant effects on outdoor environments. They assumed that temporal variations occur mainly because of receiver movement [25].…”

“…They assumed that temporal variations occur mainly because of receiver movement [25]. Therefore, time variation matrices are interpreted in terms of distance which can easily convert to time, having a receiver motion velocity.…”

Impact of Vehicular Array Position on Urban MIMO Channel Characteristics

“…Studies of vehicular-based MIMO channels were reported in [9][10][11][12][13][14][15][16][17], where the MIMO channels were measured using systems with one fixed endpoint and one vehicular-based endpoint. Lower mobility outdoor measurement campaigns have been performed using a mobile transmitter or receiver mounted on a trolley, pushed at walking speed, for example, [18][19][20]. The fixed wireless outdoor International Journal of Antennas and Propagation MIMO channel has also been investigated in urban environments, see, for example, [21][22][23][24][25].…”

On the Capacity of Printed Planar Rectangular Patch Antenna Arrays in the MIMO Channel: Analysis and Measurements [Wireless Corner]

“…Moreover, the recent decline of low-loss dielectric substrate prices has boosted their utilization, particularly in commercial communications applica tions. Their performance in multiple-input multiple-output (MIMO) systems thus seems very promising [1][2][3][4][5][6][7][8], but has to be investigated in detail.…”