Employing Broadcast Channel for Frequency Tracking in LTE-MTC Systems

To support machine type communication (MTC), new challenges for the system design have emerged. For instance, the device shall be able to setup a call at a signal-to-noise ratio (SNR) of -15dB in the extended coverage mode with only one receive antenna and almost no frequency diversity. Maintaining frequency synchronization is one of the main challenges. In this letter, we present, analyze, and evaluate a frequency tracking technique that relies on the repetitive nature of the MTC broadcast channel. Results show that this method does not only provide better performance at very low SNRs when compared to conventional techniques, but also it saves the amount of time required to lock to the network.