In this paper, the performances of different kinds of IEEE802.15.4a receivers, which are suitable for the modulation methods and their combinations defined by the standard, are compared using two dissimilar channel models for wireless body area networks. The reference channel model is the one defined by the IEEE802.15.6 standardization group, and the other one is based on the channel measurements carried out by the Centre for Wireless Communications, University of Oulu, Finland. Both channel models are targeted for wireless body area network applications. The studied information signal structure follows the IEEE802.15.4a standard, having two pulses in a burst, and either two or eight burst positions per symbol quarter. This signal structure is non-mandatory according to the standard. Following the standard, the mode with two pulses per burst and two hopping positions gives the shortest symbol duration. Because this symbol duration is shorter than a delay spread of the channel, the signal is vulnerable for severe inter-symbol interference. Our main interest is to compare the performances of this specific signal structure, with different receiver structures from the standard, and compare the results to the corresponding results of the mandatory mode signaling presented in our earlier publications.