Channel rank boosts identification capacity in MIMO communication
Gaussian Identification in MIMO Channels
Information Theory
Summary
This paper looks at how many messages can be reliably told apart in wireless communication systems that use multiple antennas at both ends (MIMO). The authors show that the number of identifiable messages can grow much faster than usual with the length of the transmission, especially when the channel has more independent paths, called rank. This means systems with higher channel rank can handle more complex message sets with strong peak limits on antenna signals. Their results explain how the channel's spatial properties give an advantage for distinguishing messages.
What this means in practice
- •For wireless network engineers: Design communication systems that exploit channel rank to allow more users to be identified simultaneously under signal constraints.
- •For satellite communication designers: Develop satellite links that maintain reliable identification of many messages using limited amplitude signals across multiple antennas.
A theory result. No direct application yet.
Authors
Mohammad Javad Salariseddigh, Christian Deppe
Abstract
We study the identification capacity of discrete-time Gaussian multiple-input multiple-output (MIMO) channels under per-antenna, per-symbol peak-amplitude constraints. We establish upper and lower bounds on the identification capacity that scale linearly with the channel rank $r.$ The number of reliably identifiable messages can grow super-exponentially with blocklength $n,$ following $M_n(R)=2^{(n\log n)R},$ where $R$ is an achievable rate. The channel rank provides a spatial-multiplexing advantage, enabling higher achievable rates and, consequently, stronger super-exponential codebook growth. These results characterize the rank-dependent gain in achievable identification performance.