A method performed at a receiving node of a wireless communication system to provide feedback to a transmitting node, the method comprising: determining a channel state of a wireless channel between the transmitting node and the receiving node based on a reference signal transmitted from the transmitting node, the channel state comprising a plurality of feedback parameters, each feedback parameter indicating a quality characteristic of the wireless channel as estimated by the receiving node or indicating a preference of the receiving node in a transmission characteristic of data transmission from the transmitting node; filling a feedback subframe based on the channel state, the feedback subframe comprising a plurality of feedback fields, each feedback field corresponding to one of the plurality of feedback parameters of the channel state and allocated to carry a value of the corresponding feedback parameter, and a field length of each feedback field being predetermined, wherein the step of filling the feedback subframe comprises: for each feedback field, generating a feedback value of the corresponding feedback parameter, for at least one feedback field, determining whether an extended value is required for the corresponding feedback parameter, wherein the step of determining whether the extended value is required for the feedback parameter corresponding to the feedback field comprises determining that the extended value is required when a feedback value of a reference feedback parameter is equal to a reference value, the reference feedback parameter being different than the feedback parameter corresponding to the feedback field, and for each feedback field that has been determined to require the extended value, generating the extended value for the corresponding feedback parameter, the extended value being a value that requires further processing to extract the feedback value; and sending a feedback signal to the transmitting node over a feedback channel, the feedback signal including the feedback subframe. determining a channel state of a wireless channel between the transmitting node and the receiving node based on a reference signal transmitted from the transmitting node, the channel state comprising a plurality of feedback parameters, each feedback parameter indicating a quality characteristic of the wireless channel as estimated by the receiving node or indicating a preference of the receiving node in a transmission characteristic of data transmission from the transmitting node; filling a feedback subframe based on the channel state, the feedback subframe comprising a plurality of feedback fields, each feedback field corresponding to one of the plurality of feedback parameters of the channel state and allocated to carry a value of the corresponding feedback parameter, and a field length of each feedback field being predetermined, wherein the step of filling the feedback subframe comprises: for each feedback field, generating a feedback value of the corresponding feedback parameter, for at least one feedback field, determining whether an extended value is required for the corresponding feedback parameter, wherein the step of determining whether the extended value is required for the feedback parameter corresponding to the feedback field comprises determining that the extended value is required when a feedback value of a reference feedback parameter is equal to a reference value, the reference feedback parameter being different than the feedback parameter corresponding to the feedback field, and for each feedback field that has been determined to require the extended value, generating the extended value for the corresponding feedback parameter, the extended value being a value that requires further processing to extract the feedback value; and for each feedback field, generating a feedback value of the corresponding feedback parameter, for at least one feedback field, determining whether an extended value is required for the corresponding feedback parameter, wherein the step of determining whether the extended value is required for the feedback parameter corresponding to the feedback field comprises determining that the extended value is required when a feedback value of a reference feedback parameter is equal to a reference value, the reference feedback parameter being different than the feedback parameter corresponding to the feedback field, and for each feedback field that has been determined to require the extended value, generating the extended value for the corresponding feedback parameter, the extended value being a value that requires further processing to extract the feedback value; and sending a feedback signal to the transmitting node over a feedback channel, the feedback signal including the feedback subframe.