An exhaustive study of modern modulation techniques is essential to the design of future systems. OFDM-based technologies, like LTE, are becoming more pervasive as LTE descendant systems have adopted this modulation technique. 5G wireless cellular systems most likely will continue this trend. For this reason it is essential to determine which components contribute to the system's performance and remove or replace those that do not. In this work, a thorough study of different subcarrier mapping distributions is done, particularly SC-LFDMA, SC-DFDMA, and SC-IFDMA. LTE upstream modulation implements SC-LFDMA, which has a high PAPR compared to SC-IFDMA. It is argued that SC-LFDMA has a high E-b/N-0, nevertheless, here it is demonstrated that only the variance of the E-b/N-0 is increased, but the average remains the same. Therefore, a low PAPR modulation technique, such as SC-IFDMA, should be selected for upstream transmissions of next-generation wireless cellular networks.