# Blind Detection with Polar Codes

## TL;DR

This paper introduces a polar code-based blind detection scheme for 5G that efficiently identifies targeted transmissions within strict time constraints, using low-complexity decoding and early stopping to optimize speed and energy use.

## Contribution

It proposes a novel polar code-based blind detection method with a low-complexity decoding process and an early stopping criterion, enhancing speed and energy efficiency in 5G systems.

## Key findings

- Achieves good missed detection and false alarm rates meeting system specs.
- Early stopping reduces average latency and energy consumption.
- System parameter tuning meets 5G timing requirements.

## Abstract

In blind detection, a set of candidates has to be decoded within a strict time constraint, to identify which transmissions are directed at the user equipment. Blind detection is an operation required by the 3GPP LTE/LTE-Advanced standard, and it will be required in the 5th generation wireless communication standard (5G) as well. We propose a blind detection scheme based on polar codes, where the radio network temporary identifier (RNTI) is transmitted instead of some of the frozen bits. A low-complexity decoding stage decodes all candidates, selecting a subset that is decoded by a high-performance algorithm. Simulations results show good missed detection and false alarm rates, that meet the system specifications. We also propose an early stopping criterion for the second decoding stage that can reduce the number of operations performed, improving both average latency and energy consumption. The detection speed is analyzed and different system parameter combinations are shown to meet the stringent timing requirements, leading to various implementation trade-offs.