Novel Scheduling Techniques with Minimal Feedback Load for Multiuser Diversity MIMO-SM Systems

Design of scheduling techniques for utilizing high data rate downlink communication in MIMO-SM systems are important area of research to take advantage of multiuser diversity in a rich scattering environment. When a part of the available bandwidth is used for feedback collections from the users, it is highly important to decrease the feedback load so that most of the bandwidth is used for downlink data communication. We report here three novel scheduling techniques with decreased feedback load using unequal quantization of system parameters, and actual number of users in the highest slot sending feedback to the base station. System parameters, depending on the channel between the transmitter and users, are designed such that with unequal quantization a few users are always there in the highest slot. We consider the bandwidth available for data transfer is used for both sending feedback in the uplink and user data transmission in the downlink in parallel channels as spatially multiplexed mode in a rich scattering environment.