Abstract: The present invention relates to a precoder and a precoding method in a multi-user multi-antenna communication System. When a transmission part (100) having a plurality of antennas transmits a plurality of signals to a receiving part (200) having an antenna, the precoder and the precoding method using the same prevents System performance degradation caused by interference signals and efficiently reduces transmission power while changing the constellation rotary angle. When the power is controlled by using the precoder, the System performance is enhanced while not damaging the structural gain of the existing multi-user multi-antenna precoder.

Abstract: Provided is method of forming a cluster individually by each sensor node over a sensor network, in which each sensor node has cluster information and authority to assign cluster membership and recognizes a sensor node that is not a cluster member in a radius of the cluster in order to include the recognized sensor node in the cluster as a cluster member. The sensor node that becomes a member of the cluster wirelessly receives an application of the cluster in order to be upgraded. Thus, after initial sensor node setting, a cluster can be formed automatically and a program suitable for each cluster can be upgraded without human intervention.