Burst vs. continuous pilot acquisition in wideband CDMA cellular mobile systems

Many future mobile communication networks will include some form of code division multiple access in their radio interface. All such systems must guarantee efficient initial code acquisition at the mobile terminal, both for call start-up and for soft-handoff handling. To this end, a spread pilot tone is generally adopted. In this paper we compare two approaches for pilot design, namely the conventional continuous pilot (CP) and a burst pilot (BP) with fractional duty cycle. We trade-off the two solutions based on acquisition error probability P_e, signal-to-noise ratio (SNR), dwell time T_d, and impact at system level. The main result is that for equal P_e and T_d the BP solution yields a considerable gain in requested SNR. However, CP can be forced to achieve the same P_e objective with the same SNR by allowing a longer T_d, and its impact at system level is considerably milder