Design of Modulation and Packet Detection in Body Area Networks

In burst communication systems like Body Area Networks (BAN), burst packet should be detected prior to the demodulation of the signal at the receiver. Meanwhile, different modulation and demodulation algorithms may affect the BER performance of the entire system seriously. To satisfy the conditions that BAN nodes or devices have to be small in size and very low in power consumption, algorithm design of modulation and packet detection are very important. Referring to IEEE 802.15.6 BAN standard, theoretical analysis of the modulation and demodulation for π/2-DBPSK and π/4-DQPSK is carried out first. The two modulations are realized by using two different two-step looking up table respectively and then united to be one by combining the two phase increment tables. By use of the special structure of π/2-DBPSK modulated preamble, packet detection algorithm with low complexity is also carefully designed. Simulation results of BER performance are presented at last. In AWGN channel, both modulations achieve good performance, and performance degradation of π/4-DQPSK happens in multipath channel which may not satisfy the requirements. Adaptive modulation is considered to solve this problem by choosing different modulation scheme according to channel quality.