N9073A W-CDMA/HSPA/HSPA+W9073A W-CDMA/HSPA X-Series Measurement Application
技术概述
Demo Guide
Demonstration Preparation
All demonstrations utilize an X-Series signal analyzer and an N5182A MXG signal generator with N7600B Signal Studio software. Keystrokes surrounded by [ ] indicate front-panel keys, while softkeys located on the right edge of the display are indicated in bold type.
The W-CDMA/HSPA/HSPA+ measurement application transforms the X-Series signal analyzers into 3GPP standard-based transmitter tester.
The application provides fast one-button RF conformance measurements to help you design, evaluate, and manufacture your W-CDMA/HSPA/HSPA+ base station and user equipment devices.
The measurement application closely follows the 3GPP standard allowing you to stay on the leading edge of your design and manufacturing challenges.
Demonstration Setup
To configure these instruments, connect the Keysight MXG’s 50 ‑ RF output to X-Series analyzer’s 50 ‑ RF input with a 50 ‑ RF cable. Turn on the power in both instruments.
Demonstration 1:
Channel power
The channel power measurement identifies the channel power within a specific bandwidth (default of 5 MHz, as per 3GPP W-CDMA technical specifications) and the power spectral density (PSD) in dBm/Hz.
Control the following channel power measurement parameters:
- Integration bandwidth (default to 5 MHz)
- Number of trace averages (default to 200)
- Data points displays, 101 to 20001 (default to 1001)
- Turn on RRC filter with flexible filter alpha value (default to Off)
- Trigger source: free run, video, line, external-½, RF burst, and periodic timer (default to free run)
Demonstration 2:
Adjacent channel power (ACP)
Reducing transmitter channel leakage allows for more channels to be transmitted simultaneously, which, in turn, increases base station efficiency. The ACP, designated by the 3GPP W-CDMA specifications as the adjacent channel leakage power ratio (ACLR), is a measure of the power in adjacent channels relative to the transmitted power.
The standard requires the power of both the transmitted and adjacent channels be measured through a root raised cosine (RRC) filter with a roll-off factor of 0.22.
Measure up to 12 carriers for multi-carrier ACP (Figure 3 shows 4-carrier W-CDMA ACP measurement)
– Adjust integration bandwidth
– Select up to six channel offsets
– Choose channel offset frequency
– Adjust and display both absolute and relative power
– View bar graph over spectrum trace
– Use built-in averaging detector (RMS) for speed and accuracy
– Turn on RRC filter with flexible filter alpha value
– Noise correction On/Off (default is Off)
Demonstration 3:
Spectrum emission mask (SEM)
The spectrum emission mask measurement required by 3GPP specifications encompasses different power limits and different measurement bandwidths (resolution bandwidths) at various frequency offsets.
Figure 4 is a diagram of the specification requirements for power density versus frequency offset from carrier (excerpt from the 3GPP TS25.104 v.8.6.0). Completing the many measurements required to comply with this standard is made quick and easy with an X-Series signal analyzer.
Demonstration 4:
Spurious emissions
The spurious emissions measurement identifies and determines the power level of spurious emissions in 3GPP defined frequency bands. The measurement allows the user to set pass/ fail limits and a reported spur threshold value. The results are conveniently displayed in a result table that can show up to 200 values.
Note: When an RMS detector is used in an X-Series analyzer, VBW is automatically set to RBW:VBW as 10:1.
This demo procedure shows how to edit the range table and how to look up the detected spurious signals. The range table refers to 3GPP TS25.141 v.8.6.0 Section 6.5.3.7.2 (Band I, Category B).
Demonstration 5:
Occupied bandwidth
The 3GPP specifications require the occupied bandwidth (OBW) of a transmitted W-CDMA signal to be less than 5 MHz, where occupied bandwidth is defined as the bandwidth containing 99% of the total channel power.
– Changeable occupied bandwidth % power
– Measure 99% occupied bandwidth and the x dB bandwidth