Synchronization is the first operation in a digital base band receiver. The accuracy of the synchronizer shapes up the performance of the base band receiver. Synchronization is broadly divided into Carrier Frequency and Phase Synchronization, Symbol Timing and Frame Synchronization. If number of false detections in frame synchronization are high then large amount of power is wasted for processing unwanted packets. In this paper, we are proposing a packet detection and transmission system with differential encoding for low power IoT networks which reduces the number of false packet detections compared to existing preamble detection techniques. The proposed frame synchronization method decides packet is valid or not by cross correlating received packet with fixed preamble sequence and determine its boundaries. The proposed system is analyzed with smart metering power data and corresponding probabilities of packet missing and false detection, power consumption and bit error rate are analyzed. At 3 dB SNR the number of false detections are reduced by 170 compared to conventional correlation method thereby saving 15.8 % of processing power at receiver. © 2015 IEEE.