Pilot Design and Channel Estimation for Uplink Block Spread CDMA

In this paper, the authors propose the pilot design and channel estimation schemes for uplink Block-Spread Code Division Multiple Access (BS-CDMA) systems. In particular, they propose the use of a common spreading code to spread the pilot signals of all users such that a high bandwidth efficiency is achieved. The expense, however, is the Multi-user Interference (MUI) introduced in uplink channel estimation. On that account, three pilot design schemes are proposed to eliminate the MUI. In particular, the performance of BS-CDMA using the proposed channel estimation methods remains robust at a Doppler frequency of 400 Hz.