On the performance of Massive MIMO systems with single carrier transmission and phase noise

Sammanfattning: In the last decade we have experienced a rapid increase in the demand for high data rates over cellular networks. This increase has been partly satisfied by the introduction of multi-user multiple-input multiple-output (MU-MIMO). In such systems, the base station (BS) is equipped with multiple antennas and the users share the time-frequency resources. However, modern communication systems are highly power inefficient. Further, the increase in demand for higher data rates is expected to accelerate in the years to come due to the popularity of mobile devices like smartphones and tablets. Hence, next generation cellular systems arerequired to exhibit high energy efficiency as well as low power  consumption. Recently, it has been shown that the deployment of a large excess of base station (BS) antennas in comparison to the served users can be a promising candidate to meet these contradictory requirements. These systems are termed as Massive MIMO. When the number of BS antennas grows large, the channels between different users become orthogonal and low complexity transceiver processing exhibits sum-rate performance that is close to optimal. In order to realize the promised gains of Massive MIMO systems, it is required that power efficient and inexpensive components are used. In contemporary cellular systems, multi-carrier transmission is used since it facilitates simple equalization at the receiver side. However, multi-carrier signals exhibit high peak-to-average-power-ratio (PAPR) and require expensive highly linear power amplifiers. Power amplifiers in this regime are also very power inefficient. On the other hand single carrier signals exhibit lower PAPR and are suitable for signal design that is more robust to non-linear power amplifiers. Further, single-carrier signals are less vulnerable to hardware impairments, such as phase noise. In this thesis we study the fundamental limits of Massive MIMO systems in terms of sum-rate performance with single-carrier transmission and phase noise and provide important insight on the design of Massive MIMO under these scenarios.