Patent ID: 8804641

Claim:
A method for detecting downlink control information, the method comprising: a relay node (RN) receiving downlink control information born in a relay physical downlink control channel (R-PDCCH) sent by an evolved Node B (eNB) to acquire a control resource; and the RN performing detection on the control resource according to an index of the control resource to acquire own control information; wherein the control resource is a Relay Control Channel Element (R-CCE) or a Physical Resource Block (PRB); the step of the RN performing detection on the control resource according to the index of the control resource to acquire own control information comprises: said RN acquiring a RN-specific search space according to a RN identity, a subframe number of a backhaul subframe, an aggregation level of a CCE/PRBs and a number of candidate control channels/PRBs; and the RN performing blind detection on the R-CCEs/PRBs in the RN-specific search space, and if a R-CCE/PRB matching with an own RN identity is detected, the downlink control information born in the R-CCEs/PRBs being RN's own control information; said RN-specific search space is: L □{( Y k +e )mod └ N k /L┘}+i where, Lε{1,2,4,8}, Lε{1,2,4}, Lε{1,2} or Lε{1}, and i=0, . . . , L−1, e=0, . . . , E (L) −1, and E (L) is the number of candidate control channels/PRBs, and N k is a total number of R-CCEs for relay link transmission or a total number of PRBs semi-statically reserved by the eNB for the relay, Y k =(A*Y k-1 )mod D, Y −1 =n RNT1 ≠0, A=39827, D=65537, k is the subframe number of the backhaul subframe, and n RNT1 is a RN identity index; the number of candidate control channels/PRBs is 6, 4 or 2; the RN detects the downlink scheduling grant information (DL grant) in a 1 st slot and detects the uplink scheduling grant information (UL grant) in a 2 nd slot; a DL grant specific search space and a UL grant specific search space of the RN are both calculated as an above formula, where, L values are same or different when calculating the DL grant specific search space and the UL grant specific search space of the RN.