Communication Relay Apparatus Selective Subcarrier Relaying

The patent applies local quality by making each relay station independently determine whether to perform relay based on its own received signal quality measurement. Instead of all relay stations uniformly participating in cooperative relay, each station locally assesses its signal quality and makes an autonomous decision, thereby improving error rate performance only where signal quality is sufficient while avoiding interference generation in areas where relay would be harmful to overall throughput.

The patent applies dynamics by making the relay operation dynamic rather than static. Relay stations continuously measure received signal quality and dynamically adjust their relay decisions based on current conditions. When signal quality is good, regenerative relay is performed to achieve optimum frame error rate; when signal quality deteriorates, relay operations are adjusted or stopped to prevent throughput degradation from reception errors.

The patent applies the intermediary principle by introducing mobile stations as intermediate relay nodes between base stations and other mobile stations. Instead of expanding coverage by adding more base stations, existing mobile stations act as intermediaries to extend the effective coverage area. This approach achieves coverage expansion without increasing the number of base stations, thereby avoiding significant system cost increases.