Centrala begrepp
Dual-antenna repeaters can be calibrated for reciprocity, enabling transparent network integration and improved beamforming.
Sammanfattning
The content discusses a reciprocity calibration method for dual-antenna repeaters in wireless networks. It covers the importance of repeaters in serving disadvantaged users, the concept of reciprocity, and the proposed calibration scheme. The calibration process involves bi-directional measurements and estimation of forward and reverse path gains to achieve reciprocity. The article also explores variations, extensions, and numerical examples to illustrate the effectiveness of the proposed method.
Structure:
- Introduction to Repeaters
- Reciprocity and Calibration
- Paper Contribution: Reciprocity-Calibration of Repeaters
- System Model
- Calibration Scheme
- An Ingenuous Approach to Estimation of β/α
- Non-Linear Least Squares (NLS) Criterion
- Basic NLS Fitting Algorithm
- Improving the Estimate by Alternating Optimization
- Numerical Example
- Variations and Extensions
- Simultaneous Calibration of Multiple Repeaters
- Concluding Remarks
Statistik
"The vectors h and g are random columns of MA×MA and MB×MB DFT matrices, modeling line-of-sight propagation between A and R and between R and B."
"The propagation channel between A and B with R off, G, has independent CN(0, 1) entries, modeling Rayleigh fading."
"The noise matrices W 0 A, W 0 B, W 1 A, and W 1 B have independent CN(0, σ2) elements; 1/σ2 is the SNR as measured at any antenna of B when one antenna at A transmits with unit power and R is off."
Citat
"Our scheme requires a reasonable SNR on the direct link (with the repeater off) to achieve good-quality estimates."
"In a deployment with many repeaters, as long as one can calibrate a first repeater, one could use it to calibrate a second repeater, even if there is no good direct-link to calibrate this second repeater, and so on."