Search Application Notes & Cards
Learn how to configure Rohde & Schwarz products to fit your application. Search our database by product, technology, or application to find relevant technical documents.
Search Application Notes & Cards
Learn how to configure Rohde & Schwarz products to fit your application. Search our database by product, technology, or application to find relevant technical documents.
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A programmable data generator such as the combination of SME with option SME-B11 is a novelty with signal generators. To make it easy for the user to get acquainted with the option and to ensure efficient operation, possible applications are described below. The data generator is used for producing binary data as well as control signals for level switching whenever digitally modulated signals are used. For a start we should like to deal in brief with the various settings available for digital modulation. Taking GSM as an example, the programming of data lists will be described next. The description for GSM can be easily applied to other digital networks as well. Next the generation of level bursts and the extension of data generator memory with option SME-B12 are described. The last section deals with special subjects such as FSK using data rates below 400 bits/s and pulse-amplitude modulation. A basic knowledge on digital modulation and TDMA will be sufficient to follow the topics.
01-Jul-1999 | AN-No. 1GPAN08
Propagation measurements are indispensable in the planning of digital, cellular mobile radio net-works. To find the optimum sites for the base stations, a mobile test transmitter system simulating the base station is operated from a number of possible locations. The test receiver system is accommodated in a vehicle, which is driven along a test route to perform measurements. The parameters measured, such as level, bit error rate or channel impulse response, provide information on the coverage within the cell. The main problem is to minimize interference caused by multipath propagation in the reception area. The SME offered by Rohde & Schwarz is a universal test generator that can be used as the core of a test transmitter system. The SME generates the GMSK-modulated signals required for GSM propagation measurements in line with the rele-vant standards. Thanks to its low weight of 17 kg it can be carried even to remote sites. Fitted with the new optional DM Memory Extension (SME-B12, in the following referred to as XMEM), the SME is able to store data sequences of up to 8 Mbit which are long enough for receiver measurements with test mobile stations. A suitable test receiver system is for instance a test mobile station for measuring level and bit error rate and the Impulse Response Analyzer PCS from Rohde & Schwarz for measuring the channel impulse response. The present Application Note describes how the XMEM can be loaded with suitable data (test sequence) by the GSM Radiocommunication Test Set CRTP from Rohde & Schwarz and how the SME has to be adjusted for GMSK modulation of these data. First, however, an overview is given of all functions of the XMEM and their operation supplementary to the Operating Manual. Finally, it is explained how the XMEM data can be transferred between PC and SME via the IEEE-488 or RS-232 interface.
01-Jul-1999 | AN-No. 1GPAN14
While Mobile phones are allowed to require approximately 3 time slots for switching from transmission to reception, base stations must be able to transmit and receive at a new frequency in every time slot in the frequency hopping mode. This behaviour must of course be tested and measurements carried out on the base station transmitter and receiver. Since there is no signal generator which is able to settle at different frequencies from one to the next time slot with GSM modulation, a solution to this problem was found by linking two Signal Generators SME in such a way that they alternately provide signals at different frequencies.
01-Jul-1999 | AN-No. 1GPAN28
Communication systems according to IS-136 (NADC) use Time Division Multiplex Access (TDMA) for the communication between base station and mobile stations. There are 6 time slots available. Depending on the amount of data, which have to be transmitted, the system uses full rate channels or half rate channels. A full rate channel means, that the mobile is accessed every 3rd time slot (e.g time slot 1 and 3, time slot 2 and 4 or time slot 3 and 6). With half rate channels the mobile is accessed every 6th time slot. Full rate and half rate channels may be mixed on demand. The base stations transmit continous on their frequency. Depending on the used combination of full rate and half rate channels the base station uses a different sequence of synchronisation words. The mobile stations use bursted transmission with one of the synchronisation words S1 to S6 defined in the standard. Signal Generator SME is excellently suited to generate these signals to test either base station receivers or mobile phone receivers. Together with the modulation data supplied with this application note the SME serves as a signal source for various test and measurement applications in the whole frequency range of IS-136 (NADC).
01-Jul-1999 | AN-No. 1GPAN35
Leaving aside the microwave generators, the present line of Rohde & Schwarz products comprisessignal generators up to 1 GHz (SMX, SMG), up to 2 GHz (SMH, SMGU), up to 3 GHz (SME, SMT) and up to 4.3 GHz (SMHU). For applications at higher frequencies, all signal generators can also be operated with an external passive frequency doubler. This extends the range of possible applications up to 8.6 GHz. Some degraded specs regarding level and modulation are described below. For people using the frequency range 3 to 6 GHz, the low priced combination SMT plus frequency doubler will mainly be interesting. Signal generator SMHU is useful for the frequency range up to 8.6 GHz. Especially the phase noise performance is excellent with this instrument. the required output signal. It should also be pointed out that the residual FM and the SSB phase noise will be 6 dB poorer as a result of frequency doubling.
20-Apr-1998 | AN-No. 1GPAN03
Signal Generator SMIQ has versatile analog and digital internal modulation capabilities. Optional Fading Simulator SMIQ-B14 adds a variety of fading functions to the integrated digital modulation capabilities of SMIQ at a highly attractive price as compared with similar products. This application note describes how to apply fading to signals of any source and with any type of modulation (analog and digital) in a very convenient way.
09-Mar-1998 | AN-No. 1MA07
Versatile Software Tool for Rohde & Schwarz Instruments
RSCommander is a versatile software tool for a wide range of Rohde & Schwarz spectrum-, network analyzers, signal generators and oscilloscopes. It allows for automatic instrument discovery, making screenshots, reading traces, file transfer and simple script creation.
24-Dec-2017 | AN-No. 1MA074