The focus of this thesis is to exploit closed-loop space–time block coding schemes designed for multiple antenna links composed of four transmit antennas within collaborative wireless networks. Such schemes have the potential to increase the end-to-end bit error rate performance of wireless networks as compared to established schemes which only include links composed of two transmit antennas. The two four transmit antenna closed-loop space–time block codes (STBCs) considered are the closed-loop quasi-orthogonal STBC (CL-QO-STBC) and the closed-loop extended-orthogonal STBC (CL-EO-STBC) schemes. Both techniques benefit from linear decoding complexity and symbolwise maximum likelihood decoding.