Systems and methods for generating a discovery signal in a device-to-device or network communication

1. A user equipment (UE) for use in device-to-device or network communication, comprising:

a processing unit; and

a memory coupled with the processing unit, the memory storing instructions, which when executed by the processor cause the processor to:

generate a plurality of multiple access symbols for transmission on a physical channel, wherein, to generate the plurality of multiple access symbols, the instructions cause the processor to:

multiply a modulation symbol with a first sequence to generate a second sequence;

apply a series of cyclic shifts to the second sequence to generate a plurality of shifted sequences;

apply at least one orthogonal code cover (OCC) of total length N to the plurality of shifted sequences;

map the orthogonal shifted sequences onto subcarriers of a plurality of physical resource blocks (PRBs) of the physical channel; and

wherein to facilitate a multiplexing function of the device-to-device or network communication, the processing unit increases at least one of:

the number of cyclic shifts, the total length of the at least one OCC, or the number of PRBs available; and

transmit the plurality of multiple access symbols on the physical channel.

2. The UE of claim 1 , wherein the number of cyclic shifts is greater than 12.

3. The UE of claim 1 , wherein the total length N of the at least one OCC is 7.

4. The UE of claim 1 , wherein, to increase the number of PRBs, the instructions cause the processor to disable frequency hopping across time slots in the physical channel.

5. The UE of claim 1 , wherein to facilitate the multiplexing function of the device-to-device or network communication, the instructions further cause the processing unit to:

modulate a data part of the plurality of multiple access symbols with a phase modulation scheme.

6. The UE of claim 1 , wherein the network comprises a 3GPP Long Term Evolution (LTE) network.

7. The UE of claim 6 , wherein the physical channel comprises a physical uplink control channel (PUCCH).

8. The UE of claim 1 , wherein the multiple access symbols comprise single-carrier frequency division multiple access (SC-FDMA) symbols.

9. The UE of claim 1 , wherein the multiple access symbols comprise orthogonal frequency division multiple access (OFDMA) symbols.

10. A 3GPP Long Term Evolution (LTE) user equipment (UE), comprising:

a processing unit; and

a memory coupled with the processing unit, the memory storing instructions, which when executed by the processing unit cause the processing unit to:

generate a plurality of multiple access symbols, wherein, to generate the plurality of multiple access symbols, the instructions cause the processing unit to:

multiply a modulation symbol with a cell specific base sequence to generate a new sequence;

apply a series of cyclic shifts to the new sequence to generate a plurality of shifted sequences; and

apply at least one orthogonal code cover (OCC) of total length N to the shifted sequences, wherein N is equal to the number of shifted sequences and each of the at least one OCCs is applied to contiguous shifted sequences; and

transmit the plurality of multiple access symbols on a physical uplink control channel (PUCCH) of an LTE network.

11. The UE of claim 10 , wherein the instructions further cause the processing unit to puncture at least one multiple access symbol to accommodate a sounding reference symbol (SRS).

12. The UE of claim 10 , wherein the instructions further cause the processing unit to apply frequency hopping to the plurality of multiple access symbols.

13. The UE of claim 10 , wherein the number of cyclic shifts is greater than 12.

14. The UE of claim 10 , wherein the multiple access symbols comprise single-carrier frequency division multiple access (SC-FDMA) symbols.

15. The UE of claim 10 , wherein the multiple access symbols comprise orthogonal frequency division multiple access (OFDMA) symbols.

16. A non-transitory computer readable storage medium having thereon instructions, which when executed by a processor, cause the processor to perform a method for device discovery in a device-to-device or network communication, the method comprising:

generating a plurality of multiple access symbols, wherein the plurality of multiple access symbols include a data part and a reference signal part;

applying an orthogonal code cover (OCC) of length N to the data part of the plurality of multiple access symbols and an OCC of length M to the reference signal part of the plurality of multiple access symbols, wherein N is equal to the number of multiple access symbols in the data part and M is equal to the number of multiple access symbols in the reference symbol part;

modulating the data part of the plurality of multiple access symbols with a phase modulation scheme; and

transmitting the plurality of multiple access symbols.

17. The non-transitory computer readable storage medium of claim 16 , wherein a modulation symbol used for the phase modulation comprises an information bit.

18. The non-transitory computer readable storage medium of claim 17 , wherein the information bit is used for differentiating between a discovery signal for device-to-device and network communication.

19. The non-transitory computer readable storage medium of claim 17 , wherein the information bit represents a scheduling request in device-to-device communication.

20. The non-transitory computer readable storage medium of claim 17 , wherein the information bit represents an emergency status in device-to-device communication.

21. A method for device discovery in a device-to-device or network communication, the method comprising:

generating, by a user equipment (UE), a plurality of multiple access symbols for transmission on a physical channel;

embedding identification information for use in device discovery in the plurality of multiple access symbols; and

transmitting the plurality of multiple access symbols on the physical channel;

wherein generating a plurality of multiple access symbols comprises:

multiplying a modulation symbol with a base sequence to generate a new sequence, wherein the modulation symbol comprises the identification information;

applying one or more orthogonal sequences to the new sequence to generate a plurality of new orthogonal sequences; and

mapping the plurality of new orthogonal sequences onto subcarriers of a plurality of physical resource blocks (PRBs).

22. The method of claim 21 , wherein the identification information comprises one of: a UE identifier, a physical cell identifier, a global cell identifier, or a device-to-device identifier.

23. The method of claim 21 , wherein the identification information includes a cluster identifier and a UE identifier.

24. The method of claim 21 , wherein the network comprises a 3GPP Long Term Evolution (LTE) network.