Patent ID: 9603138
Date: 2017-03-21
CPC Classifications: H04W

Claim:
1. A method for transmitting an Enhanced Physical Downlink Control Channel, E-PDCCH, wherein the method comprises: when downlink control information needs to be transmitted to a User Equipment, UE, in a current sub-frame in a localized transmission mode, selecting, by a base station, at least one available localized Enhanced Control Channel Element, E-CCEs, in a localized E-PDCCH time-frequency resource region of the current sub-frame at a current aggregation level; and transmitting, by the base station, the downlink control information to the UE in the selected localized E-CCE; wherein the localized E-PDCCH time-frequency resource region comprises at least one E-PDCCH resource cluster, each of which consists of at least one Physical Resource Block, PRB, pair consecutive in frequency domain in the current sub-frame; and each E-PDCCH resource cluster comprises at least one localized E-CCE, and each localized E-CCE is a set of a part of Resource Elements, REs, in a PRB pair; wherein transmitting, by the base station, the downlink control information to the UE in the selected localized E-CCE comprises: determining, by the base station, a DMRS port corresponding to the selected localized E-CCE according to a correspondence relationship, between the localized E-CCE and the DMRS port, preset for the E-PDCCH resource cluster where the selected localized E-CCE is located, and transmitting a Reference Signal (RS) for demodulation to the UE via the determined DMRS port; wherein when there are a plurality of localized E-CCEs selected, one of DMRS ports corresponding to the selected plurality of localized E-CCEs is selected in Equation 3 below, and the RS for demodulation is transmitted to the UE via the selected DMRS port: wherein n