Convolutional codes for shortpacket communication over noncoherent channels

Abstract

The design of error-correcting codes for short information blocks is becoming an increasingly relevant research area, driven by the demand for efficient transmission in emerging wireless applications. These include machine-type communications, smart metering networks, the Internet of Things, remote command links, and messaging services, all of which require a reliable and efficient transmission of small data units. For short information blocks in coherent communication systems, it has been proved that convolutional codes are able to approach performance bounds. However, synchronization using known symbols (pilot symbols) adds significant overhead when dealing with short packets. In this Master’s thesis we try to overcome this limit by analyzing convolutional codes over noncoherent channels, focusing on the use of noncoherent receivers that eliminate the need for pilot symbols. We examine this approach with both BPSK and QPSK modulation schemes, evaluating the performance of zero-tail and tail-biting convolutional codes with different memory values. Finally, we assess the complexity and performance of the proposed solutions, comparing them to known approximations of the finite-length bounds for the best possible codes in coherent channels