—mmWave wireless communication is proposed for high-throughput and high-density applications. Due to the large channel bandwidth, mmWave systems face a large variation in the observed delay spread. Many proposed single-carrier (SC) mmWave systems rely on cyclic-prefix (CP) frequency domain equalization (FDE) in order to deal with worst case channel conditions. A downside of CP-FDE receivers is their constant energy consumption independent of the actual channel conditions. The alternative overlap-save (OS) FDE receiver can adapt its complexity, but exhibits an inferior equalization performance. By proposing a hybrid FDE approach the receiver can adapt its complexity and therefor its power consumption dynamically to the given channel conditions. Using the structural similarity of overlap-save and cyclic-prefix FDE architectures the proposed hybrid receiver can switch between the two modes of operation with minimum required hardware overhead. It is shown that the proposed hybrid recei...