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Showing papers by "Thomas L. Marzetta published in 2003"


Journal ArticleDOI
TL;DR: A large component of the current interest in space–time methods can be attributed to discoveries in the late 1980s and early 1990s that a rich wireless scattering environment can be beneficial when multiple antennas are used on a point-to-point link.
Abstract: [Guest Editors introduction to: Special issue on space-time transmission, reception, coding and signal processing] Every episode of the classic 1966–1969 television series Star Trek begins with Captain Kirk’s (played by William Shatner) famous words : “Space: The final frontier….” While space may not be the final frontier for the information and communication theory community, it is proving to be an important and fruitful one. In the information theory community, the notion of space can be broadly defined as the simultaneous use of multiple, possibly coupled, channels. The notions of space–time and multiple-input multiple-output (MIMO) channels are therefore often used interchangeably. The connection between space and MIMO is most transparent when we view the multiple channels as created by two or more spatially separated antennas at a wireless transmitter or receiver. A large component of the current interest in space–time methods can be attributed to discoveries in the late 1980s and early 1990s that a rich wireless scattering environment can be beneficial when multiple antennas are used on a point-to-point link. We now know that adding antennas in a rich environment provides proportional increases in point-to-point data rates, without extra transmitted power or bandwidth.

20 citations


Patent
14 May 2003
TL;DR: In this article, a differential modulator that generates M×M unitary space-frequency signals from incoming message bits and a time-frequency transformer, coupled to the differential modulators, is used to transform the M ×M signals into space-time transmit signals for the M transmit antennas.
Abstract: Frequency-division multiplexing and demultiplexing systems and methods for use with M transmit and N receive antennas, M equaling at least two. In one embodiment, a frequency-division multiplexing system includes: (1) a differential modulator that generates M×M unitary space-frequency signals from incoming message bits and (2) a time-frequency transformer, coupled to the differential modulator, that transforms the M×M space-frequency signals into space-time transmit signals for the M transmit antennas.

9 citations


Journal ArticleDOI
Thomas L. Marzetta1
TL;DR: A one-to-one relation is obtained between the shape and orientation of a convex compact planar set and a complex-valued reflection coefficient (Schur (1917) parameter) sequence, such that the reflection coefficient magnitudes are less than or equal to one.
Abstract: We obtain a one-to-one relation between the shape and orientation of a convex compact planar set and a complex-valued reflection coefficient (Schur (1917) parameter) sequence, such that (1) the reflection coefficient magnitudes are less than or equal to one, (2) if any reflection coefficient has a magnitude equal to one, then all subsequent reflection coefficients are equal to zero, and (3) the first reflection coefficient is equal to zero. Three additional independent parameters specify the position of the set in the plane, and the size of the set (specifically its circumference). For a finite duration reflection coefficient sequence, if the last nonzero reflection coefficient has a magnitude that is less than one, then the boundary of the set is an infinitely differentiable convex curve. The boundary is a convex polygon if and only if the magnitude of the last reflection coefficient is equal to one; the number of sides of the polygon is equal to the index of the last reflection coefficient. Almost all planar convex compact sets have reflection coefficient sequences of infinite duration. Such sets can be accurately approximated with convex compact sets that are generated from relatively small numbers of reflection coefficients.

2 citations