Ultra Narrow Band is a technology that emerges as a solution to interference and congestion in certain frequency bands [1]. This technology is the progress and optimization of the Narrow Band technology, because it has limitations in optimizing spectrum usage. Two important characteristics in a UNB communications system are: a phase modulation scheme and a filter with phase response with an abrupt transition while keeping the group delay equal to zero. One of the modulation schemes that emerged for UNB technology is EBPSK. We optimize this scheme by adapting it to a quadrature system defining the detection and filtering systems and increasing effectively the transmission data rate.