PDSCH Cell Specific Ratio (LTE)

Menu Path: MeasSetup > LTE Demod Properties... > Format tab

Default: r_B/r_A = 1

Range: r_B/r_A = 1, P_B = 0, P_B = 1, P_B = 2, P_B = 3

PDSCH Cell Specific Ratio specifies the power ratio between PDSCH Physical Downlink Shared Channel resource elements and cell-specific reference signal resource elements.

When r_B/r_A = 1 is selected, the ratio r_B / r_A will be set to 1.

When P_B = (x) is selected, the LTE Long Term Evolution parameter P_B will be set to (x), and the ratio r_B / r_A will be determined from Table 5.2-1 in 3GPP TS Technical Specification 36.213. The table is reproduced below.

Table 5.2-1: The cell-specific ratio for 1, 2, or 4 cell specific antenna ports*

	rB / rA
PB	One Antenna Port	Two and Four Antenna Ports
0	1	5/4
1	4/5	1
2	3/5	3/4
3	2/5	1/2

The value r_A (dB) + C-RS Cell-specific RS Power Boost (dB) is specified in the CW0/1 Power parameter in the LTE Allocation Editor. Together, the parameters CW0/1 Power and C-RS Power Boost (specified in Downlink Control Channel Properties) determine the value of r_A. In addition, r_A and the PDSCH Cell-Specific Ratio determine the value of r_B.

The PDSCH/C-RS power ratio for the PDSCH subcarriers in each symbol is determined by Table 5.2-2 in 3GPP TS 36.213 which is shown below.

Table 5.2-2: OFDM symbol indices within a slot where the ratio of the corresponding PDSCH EPRE to the cell-specific RS EPRE is denoted by r_A or r_B *

Number of antenna ports	OFDM Orthogonal Frequency Division Multiplexing: OFDM employs multiple overlapping radio frequency carriers, each operating at a carefully chosen frequency that is Orthogonal to the others, to produce a transmission scheme that supports higher bit rates due to parallel channel operation. OFDM is an alternative tranmission scheme to DSSS and FHSS. symbol indices within a slot where the ratio of the corresponding PDSCH EPRE to the cell-specific RS EPRE is denoted by rA		OFDM symbol indices within a slot where the ratio of the corresponding PDSCH EPRE to the cell-specific RS EPRE is denoted by rB
	Normal cyclic prefix	Extended cyclic prefix	Normal cyclic prefix	Extended cyclic prefix
One or two	1, 2, 3, 5, 6	1, 2, 4, 5	0, 4	0, 3
Four	2, 3, 5, 6	2, 4, 5	0, 1, 4	0, 1, 3

For example, for a two antenna port signal with normal cyclic prefix, P_B set to 3, and r_A set to 3 dB, the power of PDSCH data subcarriers in symbols 0 and 4 would have a power r_B = 10 log(r_A / 2) = r_A - 3 dB = 0 dB.

* "© 2008. 3GPP™ TSs and TRs are the property of ARIB Association of Radio Industries and Businesses (Japan) - An incorporated body designated by the Ministry of Posts and Communication of the Japanese government to pursue effective radio utilization in the radio communication and broadcast sector. With regard to standardization, ARIB is currently primarily engaged in standardizing procedures for IMT-2000 (next generation mobile communication system) and digital TV broadcasting., ATIS, CCSA, ETSI European Telecommunications Standard Institute: The European standardization body for telecommunications., TTA Telecommunications Technology Association (Korea): A telecommunications standards setting body in Korea. and TTC Telecommunications Technology Committee (Japan): A private-sector corporate body established in 1985 to prepare domestic standards relevant to Japanese telecommunications. who jointly own the copyright in them. They are subject to further modifications and are therefore provided to you "as is" for information purposes only. Further use is strictly prohibited."

See Also

PDSCH

RS

LTE Physical Layer Overview

Format Tab

LTE Demod Properties Dialog Box