In this thesis, we investigate partner selection schemes in multiuser cooperative networks. In networks, cooperative partners adopt coded cooperation to forward signals. Among the literature, two classes of two namely, centralized partner selections and distributed partner selections, have been proposed to select appropriate relays. Centralized partner selection is able to achieve the global optimization than distributed partner selection. However, centralized partner selections require high complexity, and global channel state information, which demands large amount of overhead and waste radio resources. Especially when the size of network increases, the cost to search appropriate relay for each user dramatically increases. Hence, we consider distributed partner selection scheme in the thesis. Among the existing work, fixed priority selection algorithm is a distributed partner selection algorithm strategy; where partner assignment is based on node indices do not include any channel information. To enhance performance, we exploit the geographical information of all users. Different from other distributed partner selection schemes, we adopt the method of Carrier Sense Multiple Access to exchange local information. We proposed coverage search algorithm, nearest source search algorithm and nearest middle-point search algorithm, the serve as the criteria of partner selection. The contributions of this thesis are to raise SNR, increase the probability that the achievable rate is great than the data rate in the distributed partner selection scheme, and enhance system performance.