A novel low-complexity zero-power periods transmission technique for fast collision detection in Wireless Sensor Networks

In Wireless Sensor Networks (WSNs), transmitters sense the control channel to detect collided packets. However, such decisions at the transmitter are not an accurate indicator of collision that may occur at the receiver. In this paper, we propose a suite of novel, yet simple and power-efficient scheme to detect a collision at the receiver side without the need for full-decoding of the received packet. Our novel scheme aims at detecting collision through fast examination of the signal statistics of a short snippet of the received packet via a relatively small number of computations over a small number of received IQ samples. Hence, operating directly at the output of the receiver´s Analog-to-Digital-Converter (ADC) and eliminating the need to pass corrupted packets through the entire demodulator/decoder line-up. Accordingly, our novel approach not only reduces processing complexity and hence power consumption, but it also reduces the latency incurred to detect a collision since it operates on only a small number of samples - that may be chosen to be in the beginning of a received packet - instead of having to buffer and process the entire packet as is the case with a full-decoding approach. We also present a complexity and power-saving comparison between our novel scheme and a conventional full-decoding approach to demonstrate the significant power and complexity saving advantage of our scheme.