Transmission of device to device sounding reference signals using macrocell communication resources

1. A method performed at a first user equipment (UE) device, the method comprising:

communicating with a second UE device over a device-to-device (D2D) communication link using uplink radio resources defined by a communication specification for uplink communication between base stations and wireless communication UE devices, the uplink radio resources including uplink reference signal resources for transmitting uplink reference signals;

transmitting data and control signals to the second UE device over the D2D communication link, wherein the transmitting occurs on uplink radio resources other than the uplink reference signal resources; and

transmitting a D2D demodulation signal along with the data signals to the second UE device, the D2D demodulation signal used by the second UE device to demodulate the data signals.

2. The method of claim 1 , further comprising:

demodulating a data signal transmitted from the first UE device using the D2D demodulation signal.

3. The method of claim 1 , wherein the uplink radio resources are time-frequency communication resources having a specified times and frequencies.

4. The method of claim 3 , wherein the uplink radio resources are organized into a plurality of frequency bands and a plurality of time segments.

5. The method of claim 4 , wherein the uplink radio resources comprise a plurality of frequency bands divided in time by a series of periodically repeating frames, each frame comprising a plurality of time slots, wherein each time-frequency resource is at least one time slot and at least one frequency band.

6. The method of claim 5 , wherein the communication specification is The Third-Generation Partnership Project Long-Term Evolution (3GPP LTE) communication specification.

7. The method of claim 1 , wherein the D2D demodulation signal is scrambled with codes that are function of the first UE device.

8. The method of claim 1 , wherein the D2D demodulation signal is scrambled with codes that are function of a Cell ID of a base station.

9. A communication system comprising:

a first wireless communication user equipment (UE) device;

a second wireless communication UE device;

a base station; and

a scheduler configured to assign uplink radio resources, defined by a communication specification for uplink communication between base stations and wireless communication UE devices, as device-to-device (D2D) communication resources, the uplink radio resources including uplink reference signal resources for transmitting uplink reference signals,

the first wireless communication UE device configured to transmit data and control signals to the second wireless communication UE device over the D2D communication resources, wherein the data and control signals are transmitted on uplink radio resources other than the uplink reference signal resources,

the first wireless communication UE device further configured to transmit a D2D demodulation signal along with the data signals to the second wireless communication UE device, the second wireless communication UE device configured to use the D2D demodulation signal to demodulate the data signals.

10. The communication system of claim 9 , wherein the communication specification is The Third-Generation Partnership Project Long-Term Evolution (3GPP LTE) communication specification.

11. The communication system of claim 9 , wherein the first UE device is configured to scramble the D2D demodulation signal with codes that are function of the first UE device.

12. The communication system of claim 9 , wherein the first UE device is configured to scramble the D2D demodulation signal with codes that are function of a Cell ID of the base station.

13. A first user equipment (UE) device comprising:

a transceiver; and

a controller coupled to the transceiver, the controller including at least one processor and at least one memory, the controller configured to cause the first UE device to

communicate with a second UE device over a device-to-device (D2D) communication link using uplink radio resources of cellular communication, the uplink radio resources including uplink reference signal resources for transmitting uplink reference signals;

transmit data and control signals to the second UE device over the D2D communication link, wherein the data and control signals are transmitted on uplink radio resources other than the uplink reference signal resources; and

transmit a D2D demodulation signal along with the data signals to the second UE device, the D2D demodulation signal used by the second UE device to demodulate the data signals.

14. The first UE device of claim 13 , wherein the controller is further configured to cause the first UE device to transmit the data and control signals over the D2D communication link in accordance with The Third-Generation Partnership Project Long-Term Evolution (3GPP LTE) communication specification.

15. The first UE device of claim 13 , wherein the controller is further configured to cause the first UE device to scramble the D2D demodulation signal with codes that are function of the first UE device.

16. The first UE device of claim 13 , wherein the controller is further configured to cause the first UE device to scramble the D2D demodulation signal with codes that are function of a Cell ID of a base station.

17. A device to be equipped in a first user equipment (UE) device, the device comprising:

at least one memory; and

at least one processor coupled to the memory, the at least one processor configured to cause the first UE device to

communicate with a second UE device over a device-to-device (D2D) communication link using uplink radio resources of cellular communication, the uplink radio resources including uplink reference signal resources for transmitting uplink reference signals;

transmit data and control signals to the second UE device over the D2D communication link, wherein the data and control signals are transmitted on uplink radio resources other than the uplink reference signal resources; and

transmit a D2D demodulation signal along with the data signals to the second UE device, the D2D demodulation signal used by the second UE device to demodulate the data signals.

18. The device of claim 17 , wherein the at least one processor is further configured to cause the first UE device to transmit the data and control signals over the D2D communication link in accordance with The Third-Generation Partnership Project Long-Term Evolution (3GPP LTE) communication specification.

19. The device of claim 17 , wherein the at least one processor is further configured to cause the first UE device to scramble the D2D demodulation signal with codes that are function of the first UE device.

20. The device of claim 17 , wherein the at least one processor is further configured to cause the first UE device to scramble the D2D demodulation signal with codes that are function of a Cell ID of a base station.