Joint channel and carrier frequency offset estimation for multi-user MIMO-OFDM uplink transmissions

This article proposes a new algorithm of jointchannel and carder frequency-offset (JCCFO) estimation formulti-user multi-input and multi-output orthogonal frequencydivision multiplexing (MIMO-OFDM) systems. A least square(LS) channel estimation and a carrier frequency offset (CFO)correlation estimation are combined in this contribution. CFOsare generally estimated using training sequences in a specialsynchronization timeslot. In this contribution, CFO estimationis further improved by taking advantages of channelestimation based on pilot symbols in traffic timeslots. The CFOscan be first obtained from the primary channel estimation. Andthen, with the knowledge of the CFOs estimated, channelestimation can be enhanced greatly. Computer simulationresults indicate that the proposed JCCFO scheme is of goodperformance. Besides, the computational complexity is low.