HSDPA capacity enhancement using MIMO in a pico-cell environment

The concept of high speed downlink packet access (HSDPA) has been standardized in 3GPP for UMTS (Universal Mobile Telecommunication System). The main interest of this paper is the application of MIMO (multiple-input-multiple-output) techniques in order to achieve high data rates in HSDPA. The capacity increase available from deploying MIMO systems is obtained via the potential decorrelation between the channel coefficients of the MIMO radio channel, which can be used to create several parallel sub-channels. Along with the MIMO technique, it is mandatory to provide a metric of the channel, to be transmitted in the feedback channel by the UE (user equipment), useful for the node B (UMTS base station) to adapt the downlink transmission rate.