Line-of-sight (LoS) time-of-arrival (ToA) is one of key parameters for network-based localization techniques. Its estimation accuracy depends on the bandwidth of transmitted signals. This paper aims to investigate the LoS-ToA estimation for an interleaved OFDMA based network, where the signal bandwidth is not sufficiently wide to offer the acceptable estimation accuracy. In this situation, an oversampling approach is proposed to improve the resolution. Moreover, the proposed scheme does not require modification of mobile communications systems. It is found that the proposed approach can significantly improve the ToA estimation performance, and offer adequate accuracy even for the low signal-to-noise ratio (SNR) range. Categories and Subject Descriptors C.2.1 [Computer Communication Networks]: Wireless communication General Terms Algorithms, Design, Verification Keywords Oversampling, ToA, Positioning, OFDMA