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Positioning Reference Signals (PRS) - (Advanced LTE FDD Downlink)

PRS Overview

• PRSs are transmitted on antenna port 6.

• PRSs apply for a only.

• The positioning reference signals are not mapped to the resource elements allocated to Physical Broadcast Channels (PBCH), the Primary Synchronization Signals (P-SS) or the Secondary Synchronization Signals (S-SS) regardless of their antenna port p.

• A UE may assume that PRSs are not present in the resource blocks in which it decodes the PDSCH according to a detected PDCCH with the CRC scrambled by the SI-RNTI or a P-RNTI with DCI format 1A or 1C that is intended for the UE.

• PRSs are not transmitted in special frames.

• PRS is transmitted in N_PRS consecutive downlink frames, where N_PRS is configured by the higher layers.

• PRSs are not used for transmission of PBCH, synchronization signals, cell-specific reference signals, Multimedia Broadcast Single Frequency Network (MBSFN) reference signals or UE-specific reference signals.

• For Release 9, CSI-RS is not supported; there is no conflict between CSI-RS and PRS.

Additional Downlink parameters are described in Cell Parameters (Advanced LTE FDD Downlink), Cell Specific Reference Signal (Advanced LTE FDD Downlink), Synchronization Signals (Advanced LTE FDD Downlink), and Power Relevant Parameters (Advanced LTE FDD Downlink).

State

Choice: Off | On

Default: Off

Double-click or use the drop-down menu to enable or disable the channel. See 3GPP TS 36.211.

Power

Range: -60.000 to 20.000 dB

Default: 0.000 dB

Enter a power level in dB for the selected channel. See Output Power Calculation (Downlink) for a description of how the software applies to your power setting. See 3GPP TS 36.211.

Antenna Mapping for Port 6

Range: 0 or 1, as comma separated values (CSV), equal to the number of antennas selected.

Default: 1

Enter 0 or 1 separated by commas to assign the Positioning Reference Signals (PRS) to the physical antennas. The comma separate length is up to the Total Number of Antennas. 0 and 1 mean Off and On respectively. Comma separate sequence order means physical antenna port number.

Example: Total Number of Antennas = 4 Antennas and Antenna Mapping = [1, 1, 1, 1] case, PRS is assigned to all antennas (port 0 to 3). See 3GPP TS 36.211.

Number of PDCCH Symbols

Range: 1 to 3 (N_DL_RB > 10), 2 or 3 (N_DL_RB <= 10)

Default: 2

Enter the number of PDCCH symbols for all of the positioning reference signal (PRS) subframes.

This parameter defines the number of PDCCH OFDM symbols for all of the PRS subframes. The PRS are assigned by the Number of Consecutive DL Frames (N_PRS), PRS Configuration Index (I_PRS), PRS Periodicity (T_PRS), and PRS Subframe Offset (Delta_PRS).

If the PRS State = on and a PRS subframe is assigned, corresponding subframe of PDCCH Allocations parameters in DCI are changed by the Number of PDCCH Symbols.

• Where: N_DL_RB <= 10, the Number of PDCCH Symbols allowed is 2 or 3.

• Where: N_DL_RB > 10, the Number of PDCCH Symbols allowed is 1 to 3.

Refer 3GPP TS 36.211 and 36.331.

PRS Bandwidth

Choice: 1.4 MHz (6RB) | 3 MHz (15RB) | 5 MHz (25RB) | 10 MHz (50RB) | 15 MHz (75RB) |20 MHz (100RB)

Default: 5 MHz (25RB)

Specifies the bandwidth (resource block size) that is used to configure the positioning reference signals (PRS).

The available PRS Bandwidth setting value is determined by the System Bandwidth. If the System Bandwidth was set to less than the PRS Bandwidth, the PRS Bandwidth is automatically set the same as the System Bandwidth.

Refer 3GPP TS 36.211 and 36.355.

Number of Consecutive DL Frames (N_PRS)

Choice: 1 subframe | 2 subframes | 4 subframes | 6 subframes

Default: 1 subframe

Specifies the number of consecutive downlink subframes N_PRS with positioning reference signals (PRS).

This is a time accumulation for accuracy improvement to configure the consecutive PRS.

Refer 3GPP TS 36.211.

PRS Configuration Index (I_PRS)

Range: 0 to 2399

Default: 0

Enter the PRS Configuration Index for the positioning reference signals (PRS).

This automatically defines both the PRS Periodicity and the PRS Subframe Offset.

The first Subframe of the N_PRS downlink subframes shall satisfy (10 * SFN + Floor(Slot# / 2) - Delta_PRS) mod T_PRS = 0.

Where: Wave Generation Length < (PRS Subframe Offset + Number of Consecutive DL Frames), a part of or all of PRSs are not available for the current waveform.

Refer 3GPP TS 36.211.

PRS Periodicity (T_PRS)

Choice: 160 (subframes) | 320 (subframes) | 640 (subframes) | 1280 (subframes)

Default: 160 (subframes)

This is a read-only parameter automatically decided by PRS Configuration (I_PRS) as follows:

The first subframe of N_PRS downlink subframes shall satisfy (10 * SFN + Floor(Slot# / 2) - Delta_PRS) mod T_PRS = 0.

• I_PRS = 0 to 159 case, T_PRS = 160 (subframes).

• I_PRS = 160 to 479 case, T_PRS = 320 (subframes).

• I_PRS = 480 to 1119 case, T_PRS = 640 (subframes).

• I_PRS = 1120 to 2399 case, T_PRS = 1280 (subframes).

Where: Wave Generation Length < (PRS Subframe Offset + Number of Consecutive DL Frames), a part of or all of PRSs are not available for the current waveform.

Refer 3GPP TS 36.211.

PRS Subframe Offset (Delta_PRS)

Range: 0 to 1280 (subframes)

Default: 0 (subframe)

This is a read only parameter automatically decided by the PRS Configuration (I_PRS) as follows:

The first subframe of the N_PRS downlink subframes shall satisfy (10 * SFN + Floor(Slot# / 2) - Delta_PRS) mod T_PRS = 0.

• I_PRS = 0 to 159 case, Delta_PRS = I_PRS

• I_PRS = 160 to 479 case, Delta_PRS = I_PRS - 160

• I_PRS = 480 to 1119 case, Delta_PRS = I_PRS - 480

• I_PRS = 1120 to 2399 case, Delta_PRS = I_PRS - 1120

Where: Wave Generation Length < (PRS Subframe Offset + Number of Consecutive DL Frames), a part of or all of PRSs are not available for the current waveform.

For more detail, refer 3GPP TS 36.211.

PRS Muting Sequence Length

Choice: 2 | 4 | 8 | 16

Default: 2

Specifies the bit length of PRS Muting Sequence parameter.

PRS Muting Sequence

Range: 0 or 1 with comma separate input

Length: PRS Muting Sequence Length

Default: 1,1

Specifies PRS Muting Sequence. The value '0' means muting and '1' means not muting in the sequence.

The sequence length is defined by PRS Muting Sequence Length parameter.

If a bit in the PRS muting sequence is set to '0', the PRS is muted in the corresponding PRS positioning occasion. A PRS positioning occasion comprises of N_PRS downlink positioning subframes. The first bit of the PRS muting sequence corresponds to the first PRS positioning occasion.

Refer 3GPP TS 36.355.