A method for measuring downlink channel quality, comprising: • separately receiving, by a transmit end, a sounding reference signal of a receive end by using at least four physical antennas, wherein the at least four physical antennas are comprised in the transmit end and the at least four physical antennas comprise at least two auxiliary beam antennas and at least two macrocell antennas; • acquiring, by the transmit end, receive power of the at least four physical antennas separately for the receive end according to the sounding reference signal received within a second preset period of time; and • determining, by the transmit end according to the receive power of the at least four physical antennas separately for the receive end, that the receive end meets an initial condition of using an auxiliary beam antenna among the at least four physical antennas; • transmitting, after the determining step, by the transmit end, at least four mixed pilot signals to the receive end separately by using the at least four physical antennas, wherein the at least four physical antennas correspond to at least four logical antennas, and the at least four mixed pilot signals are separately obtained after preset pilot signals corresponding to logical antennas in the at least four logical antennas are weighted by using a precoding weight matrix; • sending, by the transmit end, a first codebook subset restriction instruction to the receive end, wherein the first codebook subset restriction instruction carries a rank indication RANK and at least one precoding matrix index, PMI, wherein the first codebook subset restriction instruction is configured and intended so that the receive end acquires downlink channel quality of an equivalent channel of an antenna specified among the at least four physical antennas according to the mixed pilot signals, the first codebook subset restriction instruction, and the preset pilot signals; and • receiving, by the transmit end, a channel quality feedback message that is fed back by the receive end according to the downlink channel quality of the equivalent channel of the specified antenna. • separately receiving, by a transmit end, a sounding reference signal of a receive end by using at least four physical antennas, wherein the at least four physical antennas are comprised in the transmit end and the at least four physical antennas comprise at least two auxiliary beam antennas and at least two macrocell antennas; • acquiring, by the transmit end, receive power of the at least four physical antennas separately for the receive end according to the sounding reference signal received within a second preset period of time; and • determining, by the transmit end according to the receive power of the at least four physical antennas separately for the receive end, that the receive end meets an initial condition of using an auxiliary beam antenna among the at least four physical antennas; • transmitting, after the determining step, by the transmit end, at least four mixed pilot signals to the receive end separately by using the at least four physical antennas, wherein the at least four physical antennas correspond to at least four logical antennas, and the at least four mixed pilot signals are separately obtained after preset pilot signals corresponding to logical antennas in the at least four logical antennas are weighted by using a precoding weight matrix; • sending, by the transmit end, a first codebook subset restriction instruction to the receive end, wherein the first codebook subset restriction instruction carries a rank indication RANK and at least one precoding matrix index, PMI, wherein the first codebook subset restriction instruction is configured and intended so that the receive end acquires downlink channel quality of an equivalent channel of an antenna specified among the at least four physical antennas according to the mixed pilot signals, the first codebook subset restriction instruction, and the preset pilot signals; and • receiving, by the transmit end, a channel quality feedback message that is fed back by the receive end according to the downlink channel quality of the equivalent channel of the specified antenna.