A method for configuring a central subcarrier, comprising: mapping (101, 201, 701, 1001, 1201, 1601) a first downlink control channel onto a part, f1, of a downlink bandwidth, fW, of a cell, and configuring a first virtual central subcarrier in f1, wherein the virtual central subcarrier refers to a subcarrier configured for an existing communication system and corresponding to a virtual baseband direct current position; and mapping (104, 204, 704, 1004, 1204, 1604) a downlink data channel onto fW of the cell, and configuring a central subcarrier on fW, wherein f1 is different or partly different from a bandwidth f2 of the cell or a neighboring cell onto which a second downlink control channel is mapped, the method being characterised in that at least one overlapping subcarrier exists between f1 and f2, or at least one idle subcarrier exists between f1 and f2, or at least one non-idle subcarrier and at least one idle subcarrier exist between f1 and f2; the first virtual central subcarrier is located in a raster for a carrier centre frequency, a frequency interval between the first virtual central subcarrier and a second virtual central subcarrier configured in f2 is an integer multiple of a frequency domain width of the subcarrier, and frequency domain borders of physical resource blocks, PRBs, are aligned between the cell and the neighboring cell; a constraint relationship of the frequency interval between the first virtual central subcarrier and the second virtual central subcarrier: n × W PRB + W SC + W Δ = m × 300 K H z m = 1,2,3,..., wherein there are n PRBs between the first virtual central subcarrier and the second virtual central subcarrier, and wherein n is a random positive integer, W PRB is a frequency domain width of the PRB, W SC is the frequency domain width of one subcarrier, W Δ is a frequency domain width of the at least one overlapping subcarrier between f1 and f2, or a frequency domain width of the at least one idle subcarrier between f1 and f2, or a frequency domain width of the at least one non-idle subcarrier and at least one idle subcarrier between f1 and f2, and m is a random positive integer. mapping (101, 201, 701, 1001, 1201, 1601) a first downlink control channel onto a part, f1, of a downlink bandwidth, fW, of a cell, and configuring a first virtual central subcarrier in f1, wherein the virtual central subcarrier refers to a subcarrier configured for an existing communication system and corresponding to a virtual baseband direct current position; and mapping (104, 204, 704, 1004, 1204, 1604) a downlink data channel onto fW of the cell, and configuring a central subcarrier on fW, wherein f1 is different or partly different from a bandwidth f2 of the cell or a neighboring cell onto which a second downlink control channel is mapped, the method being characterised in that at least one overlapping subcarrier exists between f1 and f2, or at least one idle subcarrier exists between f1 and f2, or at least one non-idle subcarrier and at least one idle subcarrier exist between f1 and f2; the first virtual central subcarrier is located in a raster for a carrier centre frequency, a frequency interval between the first virtual central subcarrier and a second virtual central subcarrier configured in f2 is an integer multiple of a frequency domain width of the subcarrier, and frequency domain borders of physical resource blocks, PRBs, are aligned between the cell and the neighboring cell; a constraint relationship of the frequency interval between the first virtual central subcarrier and the second virtual central subcarrier: n × W PRB + W SC + W Δ = m × 300 K H z m = 1,2,3,..., wherein there are n PRBs between the first virtual central subcarrier and the second virtual central subcarrier, and wherein n is a random positive integer, W PRB is a frequency domain width of the PRB, W SC is the frequency domain width of one subcarrier, W Δ is a frequency domain width of the at least one overlapping subcarrier between f1 and f2, or a frequency domain width of the at least one idle subcarrier between f1 and f2, or a frequency domain width of the at least one non-idle subcarrier and at least one idle subcarrier between f1 and f2, and m is a random positive integer.