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WCN36x0 WLAN Manufacturing Test Item Recommendations 80-WL300-55 Rev. B October 1, 2014 NO PUBLIC DISCLOSURE PERMITTED: Please report postings of this document on public servers or websites to: [email protected]. Restricted Distribution: Not to be distributed to anyone who is not an employee of either Qualcomm or its subsidiaries without the express approval of Qualcomm’s Configuration Management. Not to be used, copied, reproduced, or modified in whole or in part, nor its contents revealed in any manner to others without the express written permission of Qualcomm Atheros, Inc. Qualcomm is a registered trademark of QUALCOMM Incorporated. Atheros is a registered trademark of Qualcomm Atheros, Inc. All other registered and unregistered trademarks are the property of QUALCOMM Incorporated, Qualcomm Atheros, Inc., or their respective owners and used with permission. Registered marks owned by QUALCOMM Incorporated and Qualcomm Atheros, Inc. are registered in the United States and may be registered in other countries. This technical data may be subject to U.S. and international export, re-export, or transfer (“export”) laws. Diversion contrary to U.S. and international law is strictly prohibited. Qualcomm Atheros, Inc. 1700 Technology Drive San Jose, CA 95110 U.S.A. © 2014 Qualcomm Atheros, Inc. Revision history Revision Date Description A Jul 2014 Initial release B Oct 2014 Converted to Word document 80-WL300-55 Rev. B 2 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Contents 1 Introduction ...................................................................................................... 6 1.1 Purpose.......................................................................................................................... 6 1.2 Conventions .................................................................................................................. 6 1.3 References ..................................................................................................................... 6 1.4 Technical assistance ...................................................................................................... 6 1.5 Acronyms ...................................................................................................................... 7 2 Test Setup Example ........................................................................................ 8 3 RF FTM Performance Tests ............................................................................ 9 3.1 Recommended RF FTM performance tests .................................................................. 9 3.1.1 Tx EVM limited power test ............................................................................... 9 3.1.2 Tx SEM limited power test ................................................................................ 9 3.1.3 Rx sensitivity test ............................................................................................... 9 3.2 Recommended test procedures ..................................................................................... 9 3.2.1 Tx EVM test procedure ..................................................................................... 9 3.2.2 Tx SEM test procedure .................................................................................... 10 3.2.1 Rx sensitivity test procedure ............................................................................ 10 3.3 Further optimization ................................................................................................... 10 3.3.1 Tx EVM averaging reduction .......................................................................... 10 3.3.2 Tx and Rx packet size reduction ...................................................................... 10 3.4 Test limit formulas ...................................................................................................... 11 3.4.1 Tx EVM test limit formulas ............................................................................. 11 3.4.2 Tx SEM test limit formulas ............................................................................. 11 3.4.3 Rx sensitivity test limit formulas ..................................................................... 12 4 Recommended Minimum Test Items ........................................................... 13 4.1 Recommended minimum Tx test item ........................................................................ 13 4.2 Recommended minimum Rx test items ...................................................................... 14 80-WL300-55 Rev. B 3 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Contents Figures Figure 2-1 Production test setup .................................................................................................................. 8 80-WL300-55 Rev. B 4 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Contents Tables Table 1-1 Reference documents and standards ............................................................................................. 6 Table 3-1 Test limit formula terminology ................................................................................................... 11 80-WL300-55 Rev. B 5 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION 1 Introduction 1.1 Purpose This document provides recommendations to minimize WLAN test time performed on WCN36x0 products. The goal of the chosen test item coverage is to guarantee functional test coverage and minimal RF performance. The methodology described results in a test time of approximately 5 to 10 seconds per channel (per band) for both Tx and Rx tests combined, utilizing IEEE packet sizes. The range in time required is test equipment vendor dependent. Example WLAN total test times, not including boot time and FTM initialization, are:  Single band (WCN3620 or WCN3660/3660A/3660B/3680/3680B) − ~5 to 10 sec  Dual band (WCN3660/3660A/3660B/3680/3680B) − ~10 to 20 sec 1.2 Conventions Function declarations, function names, type declarations, and code samples appear in a different font, e.g., . #include 1.3 References Reference documents are listed in Table 1-1. Table 1-1 Reference documents and standards Ref. Document Qualcomm Technologies Q1 WLAN RF Test Guide 80-WL114-30 1.4 Technical assistance For assistance or clarification on information in this document, submit a case to Qualcomm Technologies, Inc. (QTI) at https://support.cdmatech.com/. If you do not have access to the CDMATech Support website, register for access or send email to [email protected]. 80-WL300-55 Rev. B 6 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION Introduction 1.5 Acronyms Table 1-2 Acronyms Acronym Definition CLPC closed-loop power control DPD digital pre-distortion EVM error vector magnitude FEM front-end module FTM factory test mode OLPC open loop power control SCPC self-calibrated power control SEM spectral emission mask 80-WL300-55 Rev. B 7 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION 2 Test Setup Example Figure 2-1 is an example production test setup. Figure 2-1 Production test setup 80-WL300-55 Rev. B 8 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION 3 RF FTM Performance Tests 3.1 Recommended RF FTM performance tests This chapter describes three recommended RF FTM performance tests as part of reduced test time methodology: 1. Tx EVM limited power 2. Tx Spectral Emission Mask (SEM) limited power 3. Rx sensitivity To obtain the most efficient test times, only the worst-case room temperature channel at the NOTE: worst-case rates should be measured. This can be characterized during the DVT phase of the OEM product development cycle. 3.1.1 Tx EVM limited power test Tx EVM limited power should be measured only at the highest data rate supported by the product (for example, 11n MCS7 or 11ac MCS9 and at the highest supported bandwidth) and the worst- case channel in each band. 3.1.2 Tx SEM limited power test Tx Spectral Emission Mask (SEM) limited power should be measured only at low data rates (e.g., 11b 11 Mbps and 11g/a 6 Mbps) due to maximized target power and at the worst case channel in each band. In 11b case, 11 Mbps is used to reduce packet length and minimize test time. 3.1.3 Rx sensitivity test Rx sensitivity should be measured at 2G 11b 11 Mbps, 5G 11a 6 Mbps, and the highest supported 2g/5G 11n or 11ac data rate, at the worst case single channel in each band. 3.2 Recommended test procedures 3.2.1 Tx EVM test procedure 1. Set the DUT to commanded Pout at antenna connector (measurement point). 2. Confirm that the measured power and EVM are within test limits as defined in Section 4.1. 80-WL300-55 Rev. B 9 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION RF FTM Performance Tests 3.2.2 Tx SEM test procedure 1. Set the DUT to commanded Pout at antenna connector (measurement point). 2. Confirm measured power and SEM are within test limits as defined in Section 4.1. 3.2.1 Rx sensitivity test procedure 1. Inject the DUT with target Rx Pin at antenna connector (measurement point), including OEM margin. 2. Confirm measured PER is within test limits as defined in Section 4.2. 3.3 Further optimization The test times described at the beginning of Chapter 3 reference IEEE packet sizes that are used in Qualcomm testing. To further optimize test times, two additional methods may be used. 3.3.1 Tx EVM averaging reduction The number of Tx EVM averages can be reduced below the IEEE-specified value of 20 as long as the measurements can be correlated to the IEEE-specified value of 20. The amount that a packet size can be reduced for a given test must be optimized by OEMs with their particular test equipment and corresponding test limits. For Tx testing, the lower the number of Tx EVM averages, the wider the distribution of EVM results. 3.3.2 Tx and Rx packet size reduction Tx and Rx packet size can be reduced below the IEEE-specified PSDU lengths as long as measurements can be correlated to the IEEE-specified PSDU lengths. The amount that a packet size can be reduced for a given test must be optimized by OEMs with their particular test equipment and corresponding test limits. IEEE Rx packet specifications: • 11b − PSDU length of 1024 • 11a/g − PSDU length of 1000 • 11n − PSDU length of 4096 • 11ac − PSDU length of 4096 For Rx testing, the shorter the packet length, typically the better the Rx PER performance. For Tx testing with WCN3680/3680B 11ac-capable products, there is a known FTM Tx payload packet generation limitation of 756 bytes. This limitation is not present in the normal (mission mode) operation. 80-WL300-55 Rev. B 10 Confidential and Proprietary – Qualcomm Atheros, Inc. MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION