Combining Space-Time Coding and Adaptive Sectorization Using Reflectarrays

This letter presents a new code-division multiple-access (CDMA) system architecture that combines space-time block code (STBC) transmission and adaptive sectorization using electronically tunable reflectarrays. The result is a single base station architecture that can use a combination of diversity and spatial division transmission in order to achieve good performance in a wide range of environments. The reflectarray method has the further advantage of implementing both STBC and adaptive sectorization using a single transmit chain and power amplifier. This significantly reduces the cost of deploying a multiple antenna scheme and makes it possible to retrofit combined STBC/adaptive sectorization transmission to existing single antenna base stations already in the field.