1、Subject to change Bernhard Schulz 03.2009 1MA106_2e Rohde only the main settings will therefore be described in this document. Each test sequence requires the Basic Initializing and the BT Call Setup module for call setup, and the BT Call Release module for call release. The BT Power Step module may
2、 also be required in order to step the DUT up to maximum power. Bluetooth Call Setup module The BT Call Setup module is required at the start of each Bluetooth test sequence (after Basic Initializing). The main parameters for setting up a call to a Bluetooth device are set in this module (Fig. 1). G
3、eneral 1MA106_2e 5 Rohde the CBT goes to the standby mode (Fig. 3). Fig. 3 - Call Release Configuration Fig. 4 shows the entry for Call Release in the test report. Fig. 4 Test report: Bluetooth Call Release If no call has been set up to the Bluetooth device or the call has been disconnected, a warni
4、ng is output (Fig. 5). This warning is if applicable also output by all other Bluetooth modules (except for BT Call Setup). Fig. 5 Warning: Bluetooth connection lost! General 1MA106_2e 7 Rohde & Schwarz Bluetooth Power Step module This module is required only if the DUT has to be stepped up to maxim
5、um output power. Power Step offers four alternatives for power control of the Bluetooth device (Fig. 6). Fig. 6 - Power Step The tester first inquires, via the signaling information, whether the Bluetooth device supports power control. If this is not the case, a warning is output (Fig. 7). Fig. 7 -
6、Warning: Power control not supported by the device If power control is supported, various operations can be performed. Maximum Power and Minimum Power, for example, step the power up or down until the Bluetooth device under test signals that it is transmitting at maximum or minimum power level. Fig.
7、 8 shows a typical entry for Power Step in the test report. Fig. 8 Test report: Power Step General 1MA106_2e 8 Rohde & Schwarz Prepare for Operation Setting the GPIB parameters in CBTgo The GPIB parameters of the CBT can be set via CONFIGURATION|REMOTE PORT. CBTgo uses auxiliary channels in order to
8、 communicate with additional devices. To configure an additional device, open the Configuration menu (Fig. 9) and select an Auxiliary GPIB Port. A window with further parameters will open (Fig. 10). Fig. 9 - Configuration menu General 1MA106_2e 9 Rohde & Schwarz Fig. 10 - Auxiliary GPIB Port x The d
9、evice name entered under Auxiliary GPIB Port x must be identical to the name entered in the Bluetooth modules for the individual tests. The usual GPIB parameters can be set. Note that Enable Port must be activated. Setting the reference frequency in CBTgo Via the Basic Initializing module, the CBT c
10、an be synchronized with other equipment using a 10 MHz clock signal. For this purpose, activate External 10 MHz Reference (Fig. 11), and connect a BNC cable between the REF OUT output of a generator/analyzer and the REF IN socket of the CBT. Fig. 11 Activating the external 10 MHz reference Measuring
11、 the attenuation values To obtain correct results, the attenuation between the CBT and the DUT must be measured and entered into the BT Call Setup module. Likewise, the attenuation between the DUT and the signal generator(s) and/or the spectrum analyzer must be measured and entered into the appropri
12、ate module(s). Stipulated Measurements 1MA106_2e 10 Rohde & Schwarz Rohde & Schwarz also offers the free-of-charge FreRes software which allows to record the frequency response. It is available under the following link: http:/www.rohde- Stipulated Measurements Power Density (5.1.4 TRM/CA/02/C) This
13、measurement determines the maximum transmit power of the device under test. The CBT causes the DUT to send the wanted signal in hopping mode (i.e. on all channels) and measures the DUT output power versus a specific frequency range (Fig. 12). BluetoothFrequency RangeCh 0 Ch 782402 2480 f in MHz24413
14、92321 2561Fig. 12 - Power density The Bluetooth test specification defines the following settings:Loopback or TX mode Hopping on TX at maximum power Longest possible packet type PRBS9 Spectrum analyzer: o Center frequency: 2441 MHz o Span: 240 MHz o RBW: 100 kHz o Video BW: 100 kHz o Peak detector o
15、 Max Hold o Sweep time: 1 s per 100 kHz Stipulated Measurements 1MA106_2e 11 Rohde & Schwarz Results: 1st test run: The frequency with maximum power is determined. 2nd test run: The center frequency is set to the frequency found during the 1st test run. Another measurement is performed with zero spa
16、n with a sweep time of 60 s. The transmit power must not exceed 20 dBm (100 mW). Fig. 13 shows a typical result on the FSQ. Fig. 13 - Power density, 1st test run Test setup Fig. 14 shows a typical test setup. The CBT and the DUT are connected to each other via a combiner, via which a spectrum analyz
17、er is coupled in. When using the FSL, note the following: The maximum settable reference level on the FSL is 20 dBm. An attenuator must therefore be connected ahead of the spectrum analyzer. Stipulated Measurements 1MA106_2e 12 Rohde & Schwarz Fig. 14 Test setup for power density measurement Measuri
18、ng equipment and accessories: CBT tester, FSx (FSU, FSQ, FSP, FSL) spectrum analyzer Resistive combiner: up to 2.5 GHz (e.g. Weinschel 1515-1) The measurement is performed with the BT Power Density module of CBTgo (Fig. 15). Fig. 15 - BT Power Density module Under Test mode, you can select the test
19、type, the packet type, the pattern type, the hopping scheme, and the CBT TX level. Under Analyzer, the auxiliary device name is to be entered. The name must be identical to that entered for Auxiliary GPIB Port x in the Configuration menu. Moreover, the path loss between the analyzer and the DUT as w
20、ell as the span to be covered can be entered. Under Power Density the limit for the transmit power is entered. The default settings comply with the test specification. Stipulated Measurements 1MA106_2e 13 Rohde & Schwarz CBTgo automatically performs the test with the selected settings. In the first
21、test run, the frequency with the maximum power is determined. In the second test run, which is also performed automatically, the power at this frequency is measured with zero span with a sweep time of 60 s. With the setings in compliance with the test specification, the measurement time is approx. 4
22、1 minutes . Fig. 16 shows a typical entry in the test report. Fig. 16 Test report: Power Density C/I Performance (5.1.18 RCV/CA/03/C) This measurement determines the receiver quality of the DUT if a Bluetooth interferer is present within the Bluetooth band. The result is obtained by means of a bit e
23、rror rate (BER) measurement. The wanted signal is transmitted on a single channel in non-hopping mode. A Bluetooth interferer is likewise generated on a single channel, coupled in, and the BER is determined. In the next step, the Bluetooth interferer is generated on all channels one after the other,
24、 and the BER is determined for each interferer channel. The complete test sequence is repeated twice, i.e. the BER measurement is performed with the wanted signal on three channels in total (Fig. 17). Bluetooth Frequency RangeCh 0 Ch 782402 2480 f in MHz240532441 247739 75.Fig. 17 - C/I performance
25、Stipulated Measurements 1MA106_2e 14 Rohde & Schwarz The Bluetooth test specification defines the following settings:Loopback mode Hopping off (RX/TX on single channel) Three channels (3, 39, 75) TX at maximum power DH1 PRBS9 Interferer: GFSK with PRBS15 on al Bluetooth channels in consecutive order
26、 1,600,000 bit Reference level 70 dBm For levels see Table 1 Interferer Frequency spacing Wanted signal Level, relative, above reference level Wanted signal Absolute level Interferer C / IInterferer Absolute level Co-channel 10 dB -60 dBm 11 dB -71 dBm 1 MHz 10 dB -60 dBm 0 dB -60 dBm 2 MHz 10 dB -6
27、0 dBm -30 dB -30 dBm S3 MHz 3 dB -67 dBm -40 dB -27 dBm Image frequency 3 dB -67 dBm -9 dB -58 dBm Image frequency 1 MHz 3 dB -67 dBm -20 dB -47 dBm Table 1 C/I performance levels Results: For each of the three wanted channels, the BER may exceed 0.1 % for five interferer frequencies spaced S 2 MHz
28、from the carrier (test specification: “Spurious“). For the interferer frequencies (max. five) at which the BER limit is exceeded, the BER is measured in a second test run with a C/I of 17 dB. The BER limit is again 0.1 %. Test setup Fig. 18 shows a typical test setup. The CBT and the DUT are connect
29、ed to each other via a combiner, via which the interference signal from a Bluetooth generator is coupled in. If the DUT transmits at high power levels, an attenuator may be inserted to protect the generator. Stipulated Measurements 1MA106_2e 15 Rohde & Schwarz Fig. 18 Test setup for C/I performance
30、measurement Measuring equipment and accessories CBT tester, SMx (SMU, SMJ, SMATE) signal generator Resistive combiner: up to 2.5 GHz (e.g. Weinschel 1515-1) Attenuator: up to 2.5 GHz (e.g. Suhner) The measurement is performed with the BT C/I Performance module of CBTgo (Fig. 19). Fig. 19 - BT C/I Pe
31、rformance module Stipulated Measurements 1MA106_2e 16 Rohde & Schwarz Under Test mode BER, you can select the packet type and the pattern type. Loopback Delay and Whitening can be activated. The RX and TX frequencies of the three channels can be set separately. The reference sensitivity level can be
32、 modified as required. The level of the wanted signal will be 3 dB or 10 dB above the set value, depending on the relative distance of the interferer signal (see Table 1). Under Generator, the auxiliary device name is to be entered. The name must be identical to that entered for Auxiliary GPIB Port
33、x in the Configuration menu. Moreover, the path loss between the generator and the DUT can be entered. Under Measurements, you can enter the BER limit and the number of packets. From the packet type and the number of packets, CBTgo calculates the number of bits measured and displays it. Plus, you ca
34、n enter the manufacturer-specific image frequency. The different levels are set automatically for measurements on the image-frequency channel (see Table 1). The default settings comply with the test specification. CBTgo automatically performs the test on the three channels with the selected generato
35、r settings. In the first test run, all frequencies with a BER above the set limit are determined and displayed. In the second test run, which is also performed automatically, the DUTs performance at these frequencies is retested with a C/I of 17 dB. If the connection is lost during the test, it wil
36、be re-established automatically, and “NAN“ will be stated for the BER in the test report. If CBTgo fails to re-establish the connection for a period of 10 s, the test sequence will be stopped. With the setings in compliance with the test specification, the measurement time is at least 40 minutes (10
37、 s per BER measurement 79 interferer channels three wanted channels). Fig. 20 shows a typical C/I performance test report. Fig. 20 Test report: C/I Performance Blocking Performance (5.1.19 RCV/CA/04/C) This measurement determines the receiver quality of the DUT if a CW interferer is present outside
38、the Bluetooth band. The result is obtained by means of a bit error rate (BER) measurement. The wanted signal is transmitted on a single channel in non-hopping mode. A CW interferer is likewise generated on a single channel, coupled in, and Stipulated Measurements 1MA106_2e 17 Rohde & Schwarz the BER
39、 is determined. In the next step, the CW interferer is generated at intervals of 1 MHz in consecutive order over a specific frequency range, and the BER is determined for each interferer frequency (Fig. 21). BluetoothFrequency RangeCh 0 Ch 782402 2480f in MHz24605830 2000 2400 2500 3000 12750. .Fig.
40、 21 - Blocking performance The Bluetooth test specification defines the following settings:Loopback mode Hopping off (RX/TX on single channel) Single wanted channel (58) TX at maximum power DH1 PRBS9 Wanted signal level 3 dB above reference level (70 dBm), absolute level: 67 dBm Interferer: CW in 1
41、MHz steps, for levels and frequency ranges see Table 2 and Table 3. Results: 1st test run: At each interferer frequency, 100,000 bits are measured. The frequencies at which a BER 0.1 % is obtained are recorded. Interferer Frequency range Interferer Absolute level 30 MHz to 2000 MHz 8 dBm 2000 MHz to
42、 2400 MHz 25 dBm 2500 MHz to 3000 MHz 25 dBm 3000 MHz to 12.75 GHz 8 dBm Table 2 - Blocking performance: levels for 1st test run 2nd test run: At each frequency recorded during the 1st test run, 1,600,000 bits are measured at reduced levels. The frequencies at which a BER 0.1 % is obtained are again
43、 Stipulated Measurements 1MA106_2e 18 Rohde & Schwarz recorded. The BER limit may be exceeded for a maximum of 24 frequencies. Interferer Frequency range Interferer Absolute level 30 MHz to 2000 MHz 10 dBm 2000 MHz to 2400 MHz 27 dBm 2500 MHz to 3000 MHz 27 dBm 3000 MHz to 12.75 GHz 10 dBm Table 3 -
44、 Blocking performance: levels for 2nd test run 3rd test run: At each frequency recorded during the 2nd test run (max. 24), 1,600,000 bits are measured at an absolute interference level of 50 dBm. The BER limit of 0.1 % may be exceeded for a maximum of five frequencies. Test setup Fig. 22 shows a typ
45、ical test setup. The CBT and the DUT are connected to each other via a combiner, via which the interference signal from a CW generator is coupled in. If the DUT transmits at high power levels, an attenuator may be inserted to protect the generator. Fig. 22 Test setup for blocking performance measure
46、ment Stipulated Measurements 1MA106_2e 19 Rohde & Schwarz Measuring equipment and accessories CBT tester, SMx (SMR) generator up to 12.75 GHz Resistive combiner: up to 12.75 GHz (e.g. Weinschel 1515-1) Attenuator: up to 12.75 GHz (e.g. Suhner) The measurement is performed with the BT Blocking Perfor
47、mance module of CBTgo (Fig. 23). Fig. 23 - BT Blocking Performance module Under Test mode BER, you can select the packet type and the pattern type. Loopback Delay and Whitening can be activated. The RX and the TX frequency of the measurement channel can be set separately. The reference sensitivity l
48、evel can be modified as required. The level of the wanted signal will be 3 dB above the set value. Under Generator, the auxiliary device name is to be entered. The name must be identical to that entered for Auxiliary GPIB Port x in the Configuration menu. Moreover, the path loss between the generato
49、r and the DUT can be set, and the generator level as well as a start and a stop frequency can be entered. Under BER, you can enter the BER limit and the number of packets. From the packet type and the number of packets, CBTgo calculates the number of bits measured and displays it. CBTgo automatically performs the test with the selected generator settings. The blocking performance test comprises three test runs and is very time-consuming. For this reason, it is not performed fully automatically. Any additio
