In order to solve the low utilization of spectrum resources problem and co-channel interference problem in heterogeneous network composed of cellular users and device-to-device（ D2 D） users

a new resource allocation scheme is proposed. To limit the interference of the D2 D users to the receiving of the cellular user signals by the base station

the concept of the protection area of the base station is proposed. And then the D2 D users outside the protected area are grouped

thereby reduce the mutual interference between the D2 D user links

and achieve more D2 D user multiplexes a cellular user uplink resource for communication. Finally

Selecting cellular user resources for multiplexing for each D2 D user group based on the outage probability

to ensure the communication quality of the cellular user. The simulation results show that the proposed algorithm not only can effectively reduce the cochannel interference between users

but also allows more D2 D users to access

improve system throughput and improve system fairness.