Low weight double layer coded CDMA as a novel physical layer for OneWire bus communication in sensor networks

Wired-CDMA uses a wired NOR bus and is attractive for interconnecting sensors. This paper extends previous work on a single-wire Wired-CDMA bus. It introduces new concepts for such busses, namely, low-weight codes, unary messages called Atoms, and double-layered time-distanced unary coding. The result is a non-TDMA, distributed, digital single wire bus protocol that allows sensors to communicate with each other simultaneously and asynchronously without requiring a master node. At a minimum, the enhancements double the capacity in terms of the number of the nodes on the bus for a fixed error rate, and improve by four times the data rate compared to the previous scheme.