Analysis of optimal power distribution over pilot tones for multi-carrier communications over PLC

We analyze the optimal distribution of pilot power, which will optimize the performance of multi-carrier transmissions over power lines, using comb-type pilots. To find this optimal distribution, we took noise characteristics and channel estimation techniques based on pilot tones associated with interpolation techniques into account. We used two criteria: the classic Mean Square Error of channel estimation and an indicator of performance for multi-tones systems. With these criteria, we used a recently method proposed by the authors to obtain different power distributions over pilot tones. In this paper, we analyze the errors of channel estimation obtained with two criteria and show that minimizing the performance indicator is a good criterion. Our results show that good performances can be achieved with a uniform distribution of pilot power, although the additive noise over pilots is highly colored.