iple base stations. Using adaptive precoding, the precoding matrix W is derived from the feedback received from the mobile stations, with codebook-based feedback or sounding-based feedback. In the CL-MD scheme, a single MS is served jointly by multiple coordinated base stations, whereas in the Co-MIMO scheme several mobile stations are served jointly by the multiple coordinated base stations through MU-MIMO joint scheduling and precoding. For codebook-based feedback, the mobile stations choose the PMI for the serving cell and the neighboring cells based on the channel state information. The serving BS may instruct the mobile stations to feed back 3-bit uniformly-quantized phase information for each neighboring cell, such that the BS can form a concatenated PMI based on the phase information for the neighboring cells. When a downlink multi-BS joint processing is utilized, radio resource allocation, data mapping, and pilot pattern allocation are coordinated among the participating base stations. The same data packet is transmitted by the coordinated base stations over the same radio resources. The same pilot patterns without interlacing are applied to the coordinated base stations. The operation of downlink multi-BS joint processing can be described as follows: 1. If an MS receives a Feedback Polling A-MAP IE, it will periodically send an AAI_MultiBS_ MIMO_FBK MAC control message containing the codebook feedback or will send an uplink sounding per the UL Sounding Command A-MAP IE, depending on the designated mode of operation. 2. The BS will forward the PMI(s) and coordinated PMI(s) to the neighboring base stations on receiving feedback from the mobile stations, to coordinate the utilization of the PMI(s). In the case of sounding feedback, each participating base station can perform precoding based on the received sounding signal(s) from a single MS for the CL-MD mode or from multiple mobile stations for the Co-MIMO scheme. The default number of neighboring base stations to be coordinated in order to support collab