Optimization Design of Numerical Pulse Shaping Filters for Constant Envelope With OQPSK Modulation

ZigBee technology is a bidirectional wireless communication technology with close range, low complexity, low power consumption, low data rate, and low cost, which has been standardized in IEEE 802.15.4. The offset quadrature phase-shift keying (OQPSK) modulation is a key factor for the technique of ZigBee becasue of its almost constant envelope (CE) property. In this paper, we propose numerical pulse shaping filter (PSF) design with CE property leveraging the OQPSK modulation and give optimization algorithms for the numerical PSF design under different PSF lengths (in odd or even forms), and different criteria, including minimizing the total leakage power (MTLP) and minimizing the maximum leakage power (MMLP). The designed numerical PSFs can not only keep the CE property but also have faster roll-off characteristic and less out-of-band leakage compared with the traditional analog PSFs with CE property based on the half-sine function.