Energy efficient M2M signaling with enhanced gateway: Detection and offset compensation

Machine to machine (M2M) communication networks are designed to enable communications between an ultra low-power, low-cost wireless sensor motes and the unconstrained access network. Given such asymmetric constraints in the M2M communications, effective techniques should aim to minimize the overall energy consumed in the sensor mote. We consider an M2M network with an enhanced sensor gateway (ESG), where the ESG is designed to compensate for limitations at the sensor mote. We consider energy efficient transmission at the mote, and propose spreading codes as well as a low-complexity detector at the ESG. Subsequently, we specify the frequency offset problem at the sensor mote and propose algorithms to compensate for frequency offset at ESG. We observe that the proposed detection and offset compensation scheme can perform 0.6 dB worse than the optimal detector without frequency offset.