High-SNR power offset in multiantenna communication
High-SNR power offset in multiantenna communication
Citació
- Lozano A, Tulino A M, Verdu S. High-SNR power offset in multiantenna communication. IEEE Transactions on Information Theory. 2005; 51(12): 4134-4151. DOI 10.1109/TIT.2005.858937
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Descripció
Resum
The analysis of the multiantenna capacity in the high-SNR regime has hitherto focused on the high-SNR slope (or maximum multiplexing gain), which quantifies the multiplicative /nincrease as function of the number of antennas. This traditional characterization is unable to assess the impact of prominent channel features since, for a majority of channels, the slope equals the minimum of the number of transmit and receive antennas. Furthermore, a characterization based solely on the slope captures only the scaling but it has no notion of the power required for a certain capacity. This paper advocates a more refined characterization whereby, as function of SNRjdB, the high-SNR capacity is expanded as an affine function where the impact of channel features such as antenna correlation, unfaded components, etc, resides in the zero-order term or power offset. The power offset, for which we find insightful closed-form expressions, is shown to play a chief role for SNR levels of practical interest.