This Springer Brief investigates spectrum sharing with limited channel
feedback in various cognitive radio systems, such as point-to-point,
broadcast scheduling and ad-hoc networks. The design aim is to optimally
allocate the secondary resources to improve the throughput of secondary
users while maintaining a certain quality of service for primary users.
The analytical results of optimal resource allocation are derived via
optimization theory and are verified by the numerical results. The
results demonstrate the secondary performance is significantly improved
by limited feedback and is further improved by more feedback bits, more
secondary receivers and more primary side information.