Multicarrier code-division multiple access (MC-CDMA) is an efficient method for high-speed data transmission. MC-CDMA systems are mostly affected with high peak-to-average power ratio (PAPR) and this may reduce the spectral efficiency of the system. This paper presented the PAPR reduction of a MC-CDMA using partial transmit sequence (PTS) method via whale optimization algorithm (WOA) and modified brain storm optimization (MBSO). For quadrature phase-shift keying (QPSK) modulation, our proposed method uses pseudorandom sequence (PRS) at dissimilar amount of active users. MBSO algorithm optimizes time delay and carrier frequency offset (CFO), and thus, we can minimizes the intercarrier interference from the carrier signal. Thus, we can achieve high-speed data transmission in MC-CDMA with PTS system. The results show that 64-bit QPSK has superior performances in case of bit error rate, PAPR, spectral efficiency, maximum likelihood sequence estimation, normalized mean square error, minimum mean square error, CFO, and mean square error. Hence, the performance variations for the abovementioned parameters are 60%, 23%, 12%, 15%, 40%, 5%, 14%, and 3%, respectively. These all the outcomes are taken for dissimilar modulation and the different channels.Trans Emerging Tel Tech. 2020;31:e3829.wileyonlinelibrary.com/journal/ett An adaptive combining method and a joint pre-equalization process was mentioned by Sun et al. 17 In the transmitter side, by using the controlling parameter, a method of pre-equalization is applied to compensate the selectivity of channel and improve the diversity gain. To regulate the optimum combining coefficients, a recursive least square (RLS) adaptive combining procedure is used in the receiver. The goal of RLS is to reduce the detection errors under different channel conditions. Simulation outcomes verified the better performance of the suggested method in regards of BER. The performance of modified evolutionary multiuser director (MUD) was introduced by Hung et al 18 in MC-CDMA communication systems over frequency selective fading channels (F-SFCs). In optimum detection, the genetic algorithm