IEEE Transactions on Information Theory · 2005 · 401 citations · 34 references
EngineeringElectrical EngineeringAntennasMicrowave EngineeringWireless CommunicationsAntenna ArraysAntenna DesignAntenna PolarizationAperture AntennasMimo AntennasWireless Channel ModelingAntenna Array GeometryAntenna Array ModelingAntenna TheoryBandwidthEffective ApertureMimo Channel ModelingSolid AngleSpatial Channel Modeling
Multiple‑antenna systems are constrained by the physical area and geometry of the arrays, and the conventional statistical MIMO model fails to capture these limitations. The authors aim to incorporate antenna theory to account for area and geometry constraints and define a spatial signal space that interprets experimental channel measurements in an array‑independent manner. They apply antenna theory to model the spatial signal space, enabling an array‑independent yet manageable description of the physical environment. They derive that the spatial degrees of freedom equal A|Ω| for uni‑polarized and 2A|Ω| for tri‑polarized antennas, and that the total degrees of freedom of a multiple‑antenna channel are 4WTA|Ω| when bandwidth W and time interval T are considered.
Multiple-antenna systems that are limited by the area and geometry of antenna arrays, are considered. Given these physical constraints, the limit on the available number of spatial degrees of freedom is derived. The commonly used statistical multiple-input multiple-output (MIMO) model is inadequate. Antenna theory is applied to take into account the area and geometry constraints, and to define the spatial signal space so as to interpret experimental channel measurements in an array-independent but manageable description of the physical environment. Based on these modeling strategies, for a spherical array of effective aperture A in a physical environment of angular spread |/spl Omega/| in solid angle, the number of spatial degrees of freedom is shown to be A|/spl Omega/| for uni-polarized antennas and 2A|/spl Omega/| for tri-polarized antennas. Together with the 2WT degrees of freedom for a system of bandwidth W transmitting in an interval T, the total degrees of freedom of a multiple-antenna channel is therefore 4WTA|/spl Omega/|.
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Capacity of Multi‐antenna Gaussian Channels
Emre Telatar · European Transactions on Telecommunications · 1999 · 11.3K citations · Full text