In this paper, we propose threshold-based power allocation algorithms for a recently proposed down-link switched based parallel scheduling (SBS) scheme and we present their performance results via computer simulations. As its name indicates it, the system re-allocates the extracted excess signal to noise ratio (SNR) from some acceptable users to unacceptable users among the scheduled users. After the power allocation process, the unacceptable users can reach acceptable SNRs and as such the number of effective acceptable users with an acceptable SNR threshold among the scheduled users is increased without any additional down-link transmit power. Some selected numerical results, show that the proposed power allocation algorithms offer a certain improvement in average spectral efficiency (ASE) and an increase in the average number of effective acceptable users. Although the average bit error rate (BER) performance degrades especially when the average SNR is close to the SNR threshold, this average BER performance still meets the average BER requirement.