— By the generalized multi-carrier (GMC) principle a unified framework to describe various multi-carrier as well as single carrier approaches is established. In this paper1 the GMC principle is extended to pilot design and channel estimation, so that a unified description of pilot aided channel estimation (PACE) by interpolation in time and frequency is established. This applies to frequency domain pilots which are embedded in the GMC signal, as well as pilots sequences time multiplexed with data-bearing GMC blocks. A comparative performance evaluation of the two different GMC variants OFDM and single carrier with various pilot allocation schemes is carried out, also taking into account practical constraints such as the peak to average power ratio (PAPR) and required power amplifier back-off. It is found that a serial modem with time or frequency multiplexed pilots could be designed with a power amplifier with about 2 dB lower maximum power rating than that of a corresponding OFD...