For conventional multiple-input and multiple-output (MIMO) selective decode-and-forward (S-DF) relaying network, without global channel knowledge, base station (BS) normally allocates its transmission power for the channel links between itself and its served users. In this case, if the received signal power at relay station (RS) is larger enough, RS will help BS decode and forward the messages. However, such strategy may lose system optimality if BS has the location information of RS. Motivated by this, in this paper, a RS-oriented BS power allocation algorithm for MIMO S-DF relaying is proposed to enhance the system performance. Specifically, BS firstly allocates its transmission power to help as much as data streams to be correctly decoded at RS. Then, if there is still some power left, BS will allocate the residual power for its direct channel links to the users to further increase the system performance. Computer simulations are carried out to examine the proposed scheme in terms of sumrate and bit-error-rate. It is shown that the proposed scheme outperforms the conventional schemes, especially when the RS is placed in the middle of BS and the users.
['Jiancao Hou', 'Na Yi', 'Yi Ma']
Relay-oriented source power allocation for MIMO selective decode-and-forward relaying