Trading Digital Accuracy for Power in an RSSI Computation of a Sensor Network Transceiver
Paul Detterer1,a, Cumhur Erdin1,b, Majid Nabi1,c, José Pineda de Gyvez1,d, Twan Basten1,2,f and Hailong Jiao1,e
1Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands
aP.Detterer@tue.nl
bC.Erdin@tue.nl
cM.Nabi@tue.nl
dJ.Pineda.de.Gyvez@tue.nl
eH.Jiao@tue.nl
2ESI, TNO, Eindhoven, the Netherlands
fA.A.Basten@tue.nl
ABSTRACT
To handle the rigid power and energy constraints in the Digital BaseBand (DBB) of Wireless Sensor Networks (WSN)s, we introduce approximate computing as a new power reduction method. The Received Signal Strength Indicator (RSSI) computation is a key element in DBB processing. We evaluate the trade-off in RSSI computation between Quality-of-Service (QoS) and power consumption through circuit-level approximation. RSSI elements are approximated in such a way that error propagation is minimized. In an industrial 40-nm CMOS technology, substantial energy savings up to 24% are achieved for every successfully transferred bit in DBB processing in a low-power listening WSN scenario.
Keywords: Digital Baseband, Approximate Computing, Clear Channel Assessment.
