Abstract
This paper studies the uplink channel of a time division multiple access (TDMA) cellular network assisted by wireless relays. Aiming at increasing the network's transmission rate, we optimally place multiple decode-and-forward (D&F) dedicated relays within every cell. In the first part of the contribution, we consider the relays transmitting Gaussian codewords. Results show that there is almost 39% gain in the transmission rate of each cell with respect to no relaying. In the second part, we analyze the performance impact of finite set modulation at user and relays (i.e. M-PAM). With such a modulation, the gain is slightly decreased to 27%. Finally, we show that D&F relaying provides large gains in the outage capacity at the edge of the cell, with similar performance for Gaussian and M-PAM modulation.