Optimal water-filling algorithms for a Gaussian multiaccess channel with intersymbol interference

This paper presents two novel and efficient water-filling algorithms for a two-user Gaussian multiaccess channel with intersymbol interference. These algorithms efficiently compute the optimal transmit power spectral density (PSD) for each user and obtain the capacity region of the channel. One algorithm is developed for the special case where two users have the same priorities and is more efficient than prior work. Another algorithm is designed for the first time to compute the general case where two users have different priorities. Both algorithms use a binary search technique and each has a computational complexity of O(NlogN) where N is the number of subcarriers