What is JLS (joint leakage suppression)

Joint Leakage Suppression (JLS) is a crucial technique used to mitigate interference between two or more simultaneously transmitted signals that share a common frequency band. It finds application in wireless communication systems, particularly in scenarios where multiple base stations transmit signals within the same frequency band. Let’s delve into the technical details of JLS:

1. Motivation for JLS:
   • The demand for wireless communication services has surged, leading to congestion in the available frequency spectrum.
   • Interference between different signals can degrade received signal quality, resulting in reduced strength and increased error rates.
   • JLS aims to combat this interference by exploiting the spatial diversity of received signals.
2. Spatial Diversity and Propagation Paths:
   • Spatial diversity refers to the distinct characteristics of received signals at different antennas due to their varied propagation paths.
   • These differences allow us to separate the desired signal from interference.
3. JLS Algorithm Overview:
   • The JLS algorithm operates on received signals from multiple antennas.
   • Key steps:
     • Estimation of Interference Covariance Matrix:
       • The algorithm first estimates the interference covariance matrix, which describes statistical properties of the interference.
       • Techniques for estimation include sample covariance matrix, eigenvector decomposition, or subspace decomposition of the received signal matrix.
     • Construction of Suppression Matrix:
       • The suppression matrix minimizes interference power while preserving desired signal power.
       • This optimization problem can be solved using linear programming or convex optimization.
       • Constraints ensure preservation of desired signal power.
     • Centralized vs. Distributed Architecture:
       • In the centralized architecture, all received signals go to a central processing unit for JLS.
       • In the distributed architecture, each antenna performs a local JLS, and results are combined centrally.
4. Practical Applications:
   • JLS is widely used in cellular networks, satellite communication, and radar systems.
   • By effectively suppressing interference, JLS enhances overall system performance.