Alternative Zigbee codes derived from orthogonal perfect DFT sequences

The performance of a code-division multiple access (CDMA) system is directly related with the choice of adequate codes. The codes for use in CDMA communication systems should have a perfect aperiodic (or periodic) autocorrelation function and should be orthogonal to each other at all time shifts. A mathematical property that provides a way to find large sets of real perfect DFT (discrete Fourier transform) sequences is presented. These sequences can be transformed into real orthogonal perfect DFT sequences and also into bipolar codes that have better properties than the codes used in the Zigbee communication system. These new bipolar codes are approximately orthogonal and have nearly optimum periodic and aperiodic autocorrelation functions. We also evaluate our bipolar codes with an improved error probability model.