Optimal power distribution over pilot tones for multi-carrier communications over power lines

In this paper, we propose a method for finding 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 the traditional Lagrange method to obtain different power distributions over pilot tones. In this paper, we show that minimizing the performance indicator is a good criterion, since it evolves as Bit Error Rate. We then present the optimal distribution of pilot power. 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.