USER EQUIPMENT AND METHOD FOR PACKET BASED DEVICE-TO-DEVICE (D2D) DISCOVERY IN AN LTE NETWORK
Embodiments of a User Equipment (UE) and methods for packet based device-to-device (D2D) discovery in an LTE network are generally described herein. In some embodiments, UE may be enabled for proximity services and may be configured to receive signaling from an enhanced node B (eNB) indicating resources allocated for D2D discovery. The UE may configure a discovery packet in accordance with a predetermined configuration to have at least a discovery payload and a cyclic-redundancy check (CRC). The discovery payload may include discovery-related content. The UE may be configured to transmit the discovery packet on at least some of the indicated resources for receipt by a receiving UE. In some embodiments, a demodulation reference signal (DMRS) may be selected to indicate a payload size and/or MCS of the discovery packet's payload.
1 . An apparatus of a user equipment (UE) configured for proximity communications (ProSe), the apparatus comprising: memory; and processing circuitry, configured to:
decode a system information block (SIB) from an enhanced node B (eNB), the SIB comprising discovery resource configuration information for direct UE-to-UE communications, the SIB including an indication of resources of a discovery resource pool for transmission and/or reception of discovery packets;
encode a discovery packet to include a discovery payload and a cyclic-redundancy check (CRC);
perform bit scrambling on coded bits of the discovery packet in accordance with a scrambling sequence;
configure the encoded discovery packet for transmission within the resources of the discovery resource pool; and
generate a demodulation reference signal (DMRS) for transmission within the resources of the discovery resource pool, the DMRS mapped to a base sequence configured for demodulation of the discovery packet by another UE.
2 . The apparatus of claim 1 wherein the processing circuitry is further configured to initialize the scrambling sequence with a scrambling identity at a start of each of a plurality of subframes.
3 . The apparatus of claim 2 , wherein the apparatus further comprises a sequence generator, and wherein for discovery packet transmissions, the sequence generator is initialized with the scrambling identity at the start of each subframe of the plurality.
4 . The apparatus of claim 1 , wherein the SIB indicates whether the resources of the discovery resource pool are commonly allocated for device-to-device communication, or individually allocated for direct UE-to-UE communication.
5 . The apparatus of claim 1 wherein the discovery packet is configured to be transmitted without a header.
6 . The apparatus of claim 1 wherein the resources of the discovery resource pool are scheduled periodically.
7 . The apparatus of claim 1 wherein the discovery packet is configured to have a predetermined size; and
wherein the discovery packet is encoded for transmission in accordance with a quadrature phase-shift keying (QPSK) modulation scheme
8 . The apparatus of claim 1 further comprising transceiver circuitry coupled to one or more antennas, the transceiver circuitry configured to:
receive the SIB from the eNB;
transmit the encoded discovery packet within the resources of the discovery resource pool in accordance with a modulation scheme; and
transmit the DMRS within the resources of the discovery resource pool.
9 . The apparatus of claim 8 wherein the transceiver circuitry is further configured to transmit the encoded discovery packet in accordance with a single-carrier frequency-division multiple access (SC-FDMA) technique within resources of the discovery resource pool, and
wherein the processing circuitry is configured to monitor some of the resources of the discovery resource pool for discovery announcements from other UEs.
10 . The apparatus of claim 9 wherein the processing circuitry comprises a baseband processor.
11 . A non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a user equipment (UE) to configure the UE for proximity communications (ProSe), the processing circuitry, configured to:
decode a system information block (SIB) from an enhanced node B (eNB), the SIB comprising discovery resource configuration information for direct UE-to-UE communications, the SIB including an indication of resources of a discovery resource pool for transmission and/or reception of discovery packets;
encode a discovery packet to include a discovery payload and a cyclic-redundancy check (CRC);
perform bit scrambling on coded bits of the discovery packet in accordance with a scrambling sequence;
configure the encoded discovery packet for transmission within the resources of the discovery resource pool; and
generate a demodulation reference signal (DMRS) for transmission within the resources of the discovery resource pool, the DMRS mapped to a base sequence configured for demodulation of the discovery packet by another UE.
12 . The non-transitory computer-readable storage medium of claim 11 wherein the processing circuitry is further configured to initialize the scrambling sequence with a scrambling identity at a start of each of a plurality of subframes.
13 . The non-transitory computer-readable storage medium of claim 11 , wherein the SIB indicates whether the resources of the discovery resource pool are commonly allocated for device-to-device communication, or individually allocated for direct UE-to-UE communication.
14 . The non-transitory computer-readable storage medium of claim 11 wherein the resources of the discovery resource pool are scheduled periodically.
15 . An apparatus of a user equipment (UE) configured for proximity communications (ProSe), the apparatus comprising: memory; and processing circuitry, configured to:
decode a system information block (SIB) from an enhanced node B (eNB), the SIB comprising discovery resource configuration information for direct UE-to-UE communications, the SIB including an indication of resources of a discovery resource pool for transmission and/or reception of discovery packets;
monitor some of the resources of the discovery resource pool for discovery announcements from other UEs;
decode an encoded discovery packet received within the resources of the discovery resource pool, the encoded discovery packet modulated in accordance with a predetermined modulation scheme, the discovery packet including a discovery payload and a cyclic-redundancy check (CRC); and
decode a demodulation reference signal (DMRS) received within the resources of the discovery resource pool, the DMRS mapped to a base sequence configured for demodulation of the discovery packet by the UE.
16 . The apparatus of claim 15 , wherein the SIB indicates whether the resources of the discovery resource pool are commonly allocated for device-to-device communication, or individually allocated for UE-to-UE communication.
17 . The apparatus of claim 15 wherein the resources of the discovery resource pool are scheduled periodically.
18 . The apparatus of claim 15 further comprising transceiver circuitry coupled to one or more antennas, the transceiver circuitry configured to:
receive the SIB from the eNB;
receive the encoded discovery packet within the resources of the discovery resource pool in accordance with the predetermined modulation scheme; and receive the DMRS within the resources of the discovery resource pool.