摘要 |
<p>A method of reducing a number of bits needed for a mobile station to dynamically specify an optimal precoding vector for transmissions to the mobile station from a wireless communication network that employs multi-point transmission to the mobile station from multiple geographically separated transmitter sites, the method comprising the steps of: identifying by the mobile station, from a plurality of codebooks, a codebook in which a first precoding vector resides, wherein each codebook corresponds to a particular combination of path losses between the mobile station and the plurality of transmit antennas utilized for multi-point transmission to the mobile station, and the first precoding vector is determined to be optimal under current fading conditions; transmitting from the mobile station to the wireless communication network, an identifier for the identified codebook; specifying by the mobile station, a first index identifying the first precoding vector within the identified codebook; transmitting the first index from the mobile station to the wireless communication network; receiving by the mobile station, multi-point transmissions from the multiple geographically separated transmitter sites; determining by the mobile station that fading conditions have changed, thereby making a second precoding vector within the identified codebook the optimal precoding vector; specifying by the mobile station, a second index identifying the second precoding vector within the identified codebook; and transmitting the second index from the mobile station to the wireless communication network without retransmitting the identifier for the identified codebook.</p> |