Adaptation of receiver settings in a heterogeneous network
Techniques are described for adapting receiver settings used by a mobile terminal operating in a heterogeneous network comprising macro cells and pico cells with overlapping coverage areas. A first set of subframes is allocated to the pico cells for downlink transmissions to a mobile terminal in a link imbalance zone. The mobile terminal acquires information about the subframe allocation and uses the subframe allocation information to select the signals used for adapting receiver settings used when operating in the link imbalance zone.
1. In a heterogeneous network including macro cells and pico cells with overlapping coverage, a method implemented by mobile terminal of adapting receiver settings to receive downlink transmissions from a pico cell, said method comprising:
establishing a connection with the pico cell;
receiving subframe allocation information from the network indicating a first subset of subframes reserved for downlink transmissions by the pico cell to a mobile terminal operating in a link imbalance zone;
adapting a first receiver setting for a receiver parameter based on signals transmitted only in the first subset of subframes, and adapting a second receiver setting for said receiver parameter based on signals transmitted in a second subset of subframes, wherein said first setting is for use by said mobile terminal when operating in a link imbalance zone; and
receiving and decoding data transmitted in the first subset of subframes by the pico cell using said first receiver setting for said receiver parameter and receiving and decoding data transmitted by a neighboring macro cell in said second subset of subframes using said second receiver setting for said receiver parameter when the mobile terminal is operating in a link imbalance zone.
2. The method of claim 1 wherein adapting a first receiver setting for a receiver parameter based on signals transmitted during the first subset of subframes comprises adapting a receiver setting of an automatic gain control parameter for an automatic gain control circuit based on signals transmitted in the first subset of subframes.
3. The method of claim 1 wherein adapting a first receiver setting for a receiver parameter based on signals transmitted during the first subset of subframes comprises adapting a receiver setting of an automatic frequency correction parameter for an automatic frequency correction circuit based on signals transmitted in the first subset of subframes by the pico cell.
4. The method of claim 1 adapting a first receiver setting for a receiver parameter based on signals transmitted during the first subset of subframes comprises adapting a receiver setting of a measurement parameter for a signal measurement circuit based on signals transmitted in the first subset of subframes by the pico cell.
5. The method of claim 1 further comprising performing signal quality measurements on the received signals from neighboring macro cell.
6. The method of claim 1 further comprising switching, by said mobile terminal, between said first and second receiver settings to receive signals in said first and second sets of subframes respectively.
7. A mobile terminal comprising:
a receiver to receive signals transmitted by a base station on a downlink channel;
a transmitter to transmit signals to the base station on an uplink channel;
a processor configured to:
establish a connection with a pico cell;
receive subframe allocation information from the network indicating a first subset of subframes reserved for downlink transmissions by the pico cell;
adapt a first receiver setting for a receiver parameter based on signals transmitted only in the first subset of subframes, and adapting a second receiver setting for said receiver parameter based on signals transmitted in a second subset of subframes, wherein the first receiver setting is for use when the mobile terminal is operating in a link imbalance zone; and
receive and decode data transmitted in the first subset of subframes by the pico cell using said first subset of receiver settings and receiving and decoding data transmitted by a neighboring macro cell in said second subset of subframes using said second receiver setting for said receiver parameter.
8. The mobile terminal of claim 7 wherein the processor is configured to adapt a receiver setting of an automatic gain control parameter for an automatic gain control circuit based on signals transmitted in the first subset of subframes.
9. The mobile terminal of claim 7 wherein the processor is configured to adapt a receiver setting of an automatic frequency correction parameter for and automatic frequency correction circuit based on signals transmitted in the first subset of subframes.
10. The mobile terminal of claim 7 wherein the processor is configured to adapt a signal measurement parameter receiver setting for a signal measurement circuit based on signals transmitted in the first subset of subframes by the pico cell.
11. The mobile terminal of 7 wherein the processor is further configured to perform signal quality measurements on the signals transmitted by neighboring macro cell in said second subset of subframes.
12. The mobile terminal of claim 7 wherein the processor is further configured to switch between said first and second receiver settings to receive signals in said first and second sets of subframes respectively.