Decision Fusion over Noncoherent Fading Multiaccess Channels

Abstract

In this paper, we consider a distributed detection scenario where a number of remote sensors is linked to a decision fusion center by a fading multiaccess channel. The communication is assumed to be noncoherent meaning that channel gains are unknown at both sensors and the fusion center. Each sensor makes a binary local decision and communicates it to the fusion center simultaneously. We investigate the detection performance of the system in terms of error probability and error exponent under both Rayleigh and Rician fading scenarios. We reveal that ON-OFF keying is the most energy efficient modulation scheme when the channel is subject to Rayleigh fading and that optimizing the modulation scheme can lead to a gain in error exponent under Rician fading scenario. Under both fading scenarios, optimal decision fusion rules can be reduced to simple threshold tests.

On Analog Gradient Descent Learning Over Multiple Access Fading Channels

“…where 1 {n=m} = 1 if n = m, and 1 {n=m} = 0 otherwise. The second equality follows since h n,k , h m,k are independent of g n (θ k ), g m (θ k ) for all n, m. The last equality follows since h n,k , h m,k are independent between them for n = m. Substituting (33) in (32) yields:…”

“…In our very recent work we developed an energy and spectrum efficient improved method [8]. Other related works have investigated inference over MAC for using multiple antennas at the network edge [30], detection with a non-linear sensing behavior [31], using non-coherent transmissions [32], [33], and detecting a stationary random process distributed in space and time with a circularlysymmetric complex Gaussian distribution [34], [35]. However, all these studies assume that the observation distributions are known to the nodes or to the network edge, which are assumed unknown in this paper.…”

Energy detection for decision fusion in wireless sensor networks over Ricean-mixture fading

“…λ(y) = |y| 2 , which apparently requires little computational complexity and also has the advantage that neither CSI nor SNR nor local sensor performance are needed. Such a test has been proved to be optimal in Rayleigh fading scenarios [6], [10].…”

“…For system performance evaluation, we consider the behavior of the global probability of detection (q d ) versus the global probability of false alarm (q f ), commonly denoted receiver operating characteristic (ROC). 1 Assuming real µ does not affect generality as explained in [6].…”

“…It is worth mentioning that in the specific case of Rice fading, a lowcomplexity test with optimal performance has been found[6].2014 IEEE 8th Sensor Array and Multichannel Signal Processing Workshop (SAM)…”