Distribution of Cell-Common Downlink Signals in a Hierarchical Heterogeneous Cell Deployment

A system of transmitting nodes in a wireless network, the system comprising:

• a primary, high-power, transmitting node configured to transmit cell-specific reference symbol (CRS) signals over a first coverage area, and;
• two or more secondary, low-power, transmitting nodes, each configured to transmit the same CRS signals over a coverage area that is within or substantially within the first coverage area;
• wherein said primary transmitting node and at least one of but fewer than all of said two or more secondary transmitting nodes are configured to simultaneously transmit a physical downlink data channel to a first mobile station;
• wherein the system further comprises a control element configured to select said at least one but fewer than all of the two or more secondary transmitting nodes for transmitting the physical downlink data channel to the mobile station, based on whether physical downlink data channel transmissions from each secondary transmitting node could be received by the mobile station with adequate signal strength.

A control unit for use in a wireless network having a primary, high-power, transmitting node with a first coverage area and a plurality of secondary, low-power, transmitting nodes, each having a coverage area that is within or substantially within the first coverage area, the control unit comprising:

• a network communication circuit configured to transmit and receive control information to and from said secondary transmitting nodes;
• and
• a processing circuit configured to configure said primary transmitting node to transmit cell-specific reference symbol (CRS) signals over the first coverage area;
• wherein the processing circuit is further configured to:
• configure two or more of said secondary transmitting nodes to transmit the same CRS signals;
• and
• configure said primary transmitting node and at least one of but fewer than all of said two or more secondary transmitting nodes to simultaneously transmit a physical downlink data channel to a mobile station, wherein the processing circuit is further configured to select said at least one but fewer than all of said two or more secondary transmitting nodes based on a determination of whether physical downlink data channel transmissions from each secondary transmitting node could be received by the mobile station with adequate signal strength.

A method implemented by a control unit for use in a wireless network comprising a primary, high-power, transmitting node having a first coverage area and a plurality of secondary, low-power, transmitting nodes, each having a coverage area that is within or substantially within the first coverage area, the method comprising:

• configuring said primary transmitting node to transmit cell-specific reference symbol (CRS) signals over the first coverage area;
• configuring two or more of said secondary transmitting nodes to transmit the same CRS signals;
• configuring the primary transmitting node and at least one of but fewer than all of the two or more secondary transmitting nodes to simultaneously transmit a physical downlink data channel to a mobile station;
• selecting said at least one but fewer than all of the two or more secondary transmitting nodes based on a determination of whether physical downlink data channel transmissions from each secondary transmitting node could be received by the mobile station with adequate signal strength.