Anritsu Vector Signal Generator/Signal Analyzer Solution Addresses LTE-Advanced Carrier Aggregation Test Requirements
By Patrick Weisgarber, Anritsu Company
LTE-Advanced, unveiled by 3GPP Release 10, incorporates Carrier Aggregation (CA) to address the spectrum congestion associated with the increased use of rich applications by a growing number of consumers. It also addresses the need for backward compatibility by using LTE Release 8 and Release 9 carriers as basic building blocks.
While LTE-Advanced CA was developed to solve the dilemma of increased user expectations for ubiquitous coverage, instantaneous response and bandwidth on demand, it has created testing challenges for engineers designing User Equipment (UE) and base stations. Anritsu Company addresses these challenges with flexible test solutions specifically developed for evaluating the performance of devices that implement LTE-Advanced CA technology.
The MS269xA (Figure 1) series of spectrum/signal analyzers consists of three models—the MS2690A/MS2691A/MS2692A—that provide frequency coverage up to 26.5 GHz. The MS269xA delivers unique versatility to engineers by combining high-performance vector signal analysis and full-featured vector signal generation into a single instrument. The series features the high dynamic range and low distortion necessary for LTE-Advanced CA device validation. A patented multipoint amplitude and phase calibration process enables a best-in-class level accuracy of ±0.5 dB throughout the LTE-Advanced operating bands, eliminating the need for a RF power meter in many cases.
To simplify the testing of LTE-Advanced components and devices, the MS269xA incorporates a variety of automated spectrum measurements, including channel power, occupied bandwidth, Adjacent Channel Leakage Ratio (ACLR) and Spurious Emissions. The instrument also offers comprehensive LTE-Advanced FDD and TDD modulation measurements, including Error Vector Modulation (EVM), frequency error, timing error and subcarrier power for every subframe, resource block and symbol within an LTE signal.
The MS269xA enables easy, one-button evaluation of up to five Component Carriers (CC) across up to three RF bands of 125 MHz each, making it suitable for any current or proposed LTE-Advanced CA scenario. The signal analyzer can accommodate any combination of Intraband Contiguous, Intraband Non-contiguous and Interband Non-contiguous Component Carriers and displays all measurement results on a single screen (Figure 2).
An optional vector signal generator in the MS269xA provides coverage up to 6 GHz and features a modulation bandwidth of 120 MHz, making it suitable for modeling any current or proposed Intraband Contiguous and Non-contiguous CA scenario. Integration of the vector signal generator in the MS269xA allows engineers to use a single instrument for Tx/Rx stimulus/response and gain/distortion testing on LTE-Advanced devices and components.
Vector Signal Generator
The MG3710A vector signal generator (Figure 3) offers coverage to 6 GHz and provides the high output power and spectral purity required for LTE-Advanced CA testing. With dual RF output ports and dual memories for each port, the MG3710A can generate up to four independently modulated 120 MHz bandwidth signals—each of which may be tuned in frequency and amplitude.
Engineers can use the multi-signal generation capability of the MG3710A to test LTE-Advanced devices and components. One MG3710A can simulate up to 20 CCs across two frequency bands, enabling it to model any current or proposed Intraband Contiguous, Intraband Non-contiguous and two-band Interband Non-contiguous CA scenario. When combined with the vector signal generator in the MS269xA, the two instruments can model even the most complex scenario proposed for LTE-Advanced: five CCs across three bands.
The MG3710A can generate the high-purity LTE-Advanced signals required for characterizing the gain and distortion of components, such as amplifiers, duplexers, mixers and antenna switch modules, used in LTE-Advanced base stations and UE.
The MG3710A supports all required base station and UE receiver tests, including In-Channel and Adjacent Channel Selectivity; In-band, Out-of-Band and Narrow Band Blocking; and Spurious Response, Intermodulation and Receiver Image Rejection. A wide range of 3G and 4G reference waveforms enables the MG3710A to be used for Co-location and Co-Existence testing used in LTE-Advanced base station and UE.
Software Simplifies LTE-Advanced CA Testing
Anritsu’s IQproducer™ software simplifies the generation of customized waveforms. IQproducer enables the user to easily configure and create complex LTE-Advanced FDD and TDD CA signals via an intuitive user interface.
Figure 4 shows the Easy Setup mode of IQproducer. Key CC parameters can be confirmed via a list display, and the bandwidth, Cell ID, frequency offset, and E-UTRA Test Model can be set for each CC. A Normal Setup mode supports more detailed settings.
Carrier Aggregation is a key LTE-Advanced technology, offering faster and larger capacity mobile services over a wider coverage range. However, the multi-signal environment inherent to CA introduces complexity to evaluating and characterizing LTE-Advanced devices. The Anritsu MS269xA spectrum/signal analyzers and MG3710A vector signal generator comprise a versatile two-box solution that can handle the most complex LTE-Advanced CA signal analysis and generation—as well as every other common 3G and 4G wireless technology.
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