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Distortion Outage Minimization and Diversity Order Analysis for Coherent Multiaccess.
- Source :
-
IEEE Transactions on Signal Processing . Dec2011, Vol. 59 Issue 12, p6144-6159. 16p. - Publication Year :
- 2011
-
Abstract
- In this paper, we investigate the distortion outage performance of distributed estimation schemes in wireless sensor networks, where a distortion outage is defined as the event that the estimation error or distortion exceeds a predetermined threshold. The sensors transmit their observation signals using the analog amplify and forward scheme through coherent multiaccess channels to the fusion center, which reconstructs a minimum mean squared error (MMSE) estimate of the physical quantity observed. We consider three power allocation schemes: 1) equal power allocation (EPA); 2) short-term optimal power allocation (ST-OPA), where we minimize the distortion subject to a power constraint at each time step; and 3) long-term optimal power allocation (LT-OPA), where we minimize the distortion outage probability subject to a long-term average power constraint. We study their diversity orders of distortion outage in terms of increasing numbers of sensors, and show that under Rayleigh fading EPA and ST-OPA achieve the same diversity order of N\log N, where N is the number of sensors. This suggests that in the case of a large number of sensors, the spatial diversity gain in EPA can overcome fading equally well as in ST-OPA. On the other hand, in LT-OPA, we find that for N>1 the outage probability can be driven to zero with a finite amount of total power. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 1053587X
- Volume :
- 59
- Issue :
- 12
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Signal Processing
- Publication Type :
- Academic Journal
- Accession number :
- 67227219
- Full Text :
- https://doi.org/10.1109/TSP.2011.2165950