In co-channel deployment of macro cell and pico cells, cell range extension (RE), a simple and typical cell association scheme, is introduced to achieve better load balancing and improve cell edge performance.In this article, a novel dynamic and distributed bias setting scheme is proposed for RE technique in macro-pico heterogeneous networks.In this strategy, the worst user throughput of each cell during an adjusting time interval T is obtained to change the bias values according to certain procedures, where an introduced indicator is used to freeze the possibility of increasing bias value if needed.Furthermore, silent state and coarse control process are employed to achieve low overheads and computational complexity.Simulation results show that the proposed scheme can greatly improve the cell-edge performance compared with the static bias setting strategies, while maintaining the overall cell performance at the same time. In co-channel deployment of macro cells and pico cells, cell range extension (RE), a simple and typical cell association scheme is introduced to achieve better load balancing and improve cell edge performance. In this article, a novel dynamic and distributed bias setting scheme is proposed for RE technique in macro-pico heterogeneous networks. In this strategy, the worst user throughput of each cell during an adjusting time interval T is obtained to change the bias values ​​according certain certain, where an introduced indicator is used to freeze the possibility of increasing bias value if needed.Furthermore, silent state and coarse control processes are employed to achieve low overheads and computational complexity.Simulation results show that the proposed scheme can greatly improve the cell-edge performance compared with the static bias setting strategies while while maintaining the overall cell performance at the same time.