Wavelet Packet division multiplexing (WPDM) is a high capacity, flexible and robust orthogonal multiplexing technique in which the signals are coded onto wavelet packet basis functions for transmission. In contrast to the conventional tune division multiplexing (TDM) and frequency division multiplexing (FDM) the waveforms used to represent the data symbols of each user overlap in both time and frequency, but their orthogonality properties ensure that the overlapping message signals can be separated by a simple correlator receiver.The localization properties of the coding waveforms provide some robustness to the effects of tuning error, but at the same time these properties make the system highly susceptible to the frequency-selective channel effects. To reduce these effects, a Branch-Hopped WPDM scheme with a suggested hopping strategy was employed and a method for re-designing the coding wavelets for spread spectrum application was also presented. The proposed WPDM system was simulated and examined under various environment conditions such as Gaussian noise, jamming and timing errors. Simulation results show a capacity improvement is offered by the use of WPDM system over the commonly used FDM and TDM schemes. They also show the system robustness to timing errors as compared to the CDMA system. For the BH-WPDM, simulation results show that a further robustness is provided to single tone jamming effect under a given switching strategy. Moreover the performance improvement of the designed coding wavelets over both Haar and Daubechies wavelets was also demonstrated by simulation results. Under the effect of single tone jamming, the amount of the SNR improvement was about 4dB at 104 BER with signal-to-jamming power ratio of 10dB.