Multicarrier systems have shown better performance measures when system parameters (power, bits etc.) are optimized over different frequencies with respect to the channel gain factor. On the other hand stringent wireless spectrum constraints requiring inter-system spectrum sharing are giving birth to peak-power constrained multicarrier systems like MB-OFDM (A. Batra et al., 2004) based UWB system that rely on limiting peak emission power in order to inhibit interference with other systems using the same frequency spectrum. Power optimization for such systems must incorporate the additional peak-power constraint and at the same time respect the crucial time constraints of a very high data-rate system like that of UWB. This work addresses both of these issues by first analytically solving the peak power constrained BER minimizing power allocation problem and finally an important contribution comes in the development of a simplistic implementation algorithm which is found to converge faster than some recently proposed solutions based on iterative waterfilling for optimal power allocation in peak-power constrained systems.