Orthogonal Data Repetition Patterns for Massive Connectivity

Abstract

One of the main requirements in the next generation wireless and mobile communication system is supporting a huge number of machine type communication (MTC) devices efficiently. MTC devices may be placed in indoor or underground environments, where the signal is hard to reach. In order to maintain a proper communication range, devices with bad channel conditions may use very low data rates using data repetitions. However, the performance of devices with long packet lengths may be degraded due to increased collisions with other short packets. In this paper, we propose random access schemes using orthogonal data repetition patterns to reduce the collision probability of devices with bad channel conditions.