Total Isotropic Sensitivity Measurements Research Articles

The Effects of the Use of DRx Antenna Structure on the Rx Performance of Smartphones

Receiving the power emitted from the base station by smart phones and providing effective signaling is seen as a very critical problem. In order to eliminate this situation, some antenna technologies have been developed and started to be used in smart devices. The smart phones, which were developed by adhering to the DRx (Diversity Receive) design scheme, best perceived the signals emitted from the base station, thus increasing the Rx performance of the developed products. Typical integrated (total) surface metrics include Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS). TIS and TRP metrics have become increasingly important for carriers, because a TRP measurements used to verify your transmitter or transmitter antenna design. A TIS measurement used to verify how your receiver or receiver antenna design performs. In this study, we aimed to determine the Rx performance of the DRx scheme used in smartphones by using 3D radiation test setup (TIS - Total Isotropic Sensitivity).

Effects of User Proximity on Total Radiated Power and Total Isotropic Sensitivity Measurements in Reverberation Chambers

Effects of User Proximity on Total Radiated Power and Total Isotropic Sensitivity Measurements in Reverberation Chambers

Effects of Signal Bandwidth on Total Isotropic Sensitivity Measurements in Reverberation Chamber

Nowadays, wireless devices exhibit an explosive growth trend, which imposes great challenges on over-the-air (OTA) testing. Obviously, the reliability and efficiency of OTA testing have significant influences on the research and development of wireless devices. The reverberation chamber (RC) has become an efficient solution to OTA tests such as total isotropic sensitivity (TIS), especially for large-form-factor devices. In this work, the signal bandwidth (BW) effect on the TIS measurement of a long term evolution (LTE) device is analyzed in a comprehensive way. It is theoretically and experimentally verified that the measurement uncertainty is lower for the case of larger signal BW, and vice versa. This indicates the signal BW effects contribute to the measurement uncertainty and must be considered. The findings of this work allow more flexible and efficient TIS measurements.

A Unified Approach for Uncertainty Analyses for Total Radiated Power and Total Isotropic Sensitivity Measurements in Reverberation Chamber

With the rapid development and explosive application of the internet of things (IoT) technology, IoT devices become ubiquitous and indispensable in people’s daily lives. IoT devices with various forms and massive production impose challenges on their over-the-air (OTA) testing. Nowadays, conducting OTA testing in an efficient, reliable, and cost-effective way has become an urgent demand for the IoT industry. Owing to the particular properties (e.g., low cost, high efficiency, and good repeatability) of the reverberation chamber (RC), it has become a popular OTA testing facility. This article analyzes the statistical uncertainties of two fundamental metrics for IoT devices, i.e., the total radiated power (TRP) and the total isotropic sensitivity (TIS), measured in the RC. Based on the derived probability density functions (PDFs) and associated statistics, a unified approach for uncertainty analyses of TRP and TIS has been proposed, which can greatly facilitate the uncertainty characterizations in the OTA testing.

Total Isotropic Sensitivity Measurement in Switched Beam Antenna Systems

Smart antenna systems (SAS) play an important role in wireless communication systems, especially in rapidly developing fifth-generation (5G) systems. In normal device under test (DUT) applications with SAS, the antenna’s state may change in different external environments in order to obtain higher antenna gains and better connection with the base station, resulting in high uncertainties for over-the-air (OTA) tests using conventional methods. Before evaluating the transceiver performance, additional application programs are necessary to control the DUT, which increases the inconvenience for engineers and makes it impossible to reflect the real usage scenario. This article proposes a new convenient method for total isotropic sensitivity (TIS) measurement of each antenna group in SAS with multiple groups of antennas. This method monitors the status of the antenna systems, and the TIS is calculated from the received signal strength indicator (RSSI). The proposed method is suitable for Global System for Mobile Communications (GSM), wide band code division multiple access (WCDMA), long term evolution (LTE), and other wireless communication systems with RSSI report.

Notice of Retraction: Objective Total Isotropic Sensitivity Measurement

The characterization of the performance of wireless devices plays a significant role in developing radio products that meet the demands of the latest standards and deliver a satisfying user experience. With current standard total isotropic sensitivity (TIS) measurement, the transmitters are set to work at their maximum transmission power level. However, the standard TIS test procedure is unable to accurately reflect a receiver's performance because in actual usage transmitters are rarely working at their maximum power level. In measurements, different kinds of devices hold different maximum power levels. The measured radio sensitivity depends on the instantaneous local temperature of the radio, and the local temperature depends on the heat generation (power levels), the heat dissipation, and time. So the power levels and the thermal conditions could affect their radio sensitivity and, hence, the TIS. With standard TIS methods, the maximum power level and the radio's thermal condition cause ambiguity in the measurements. However, this paper proposes a new objective TIS method. With this new TIS method, the measured TIS is a function of the transmitter power level at its thermally stable condition. The proposed method resolves the ambiguity of the TIS measurement.

Fast and Accurate TIS Testing Method for Wireless User Equipment With RSS Reporting

A fast and accurate total isotropic sensitivity (TIS) testing method for wireless user equipment based on radiated sensitivity measurement and received signal strength (RSS) reporting is proposed in this paper. Innovative techniques for avoiding the effects of RSS reporting errors on TIS accuracy and reducing the total TIS measurement time are presented and incorporated into the testing procedures. The proposed method is suitable for receiver sensitivity testing of single input, single output radio systems having RSS reporting such as cellular communication, WiFi, and Bluetooth systems.

Fast Band-Sweep Total Isotropic Sensitivity Measurement

To provide consistent measurements of radio performance in typical complex environments, the total isotropic sensitivity (TIS) is used as a key parameter measured in anechoic chambers. Currently, the TIS measurement is based on the integration of the measured effective isotropic sensitivity at every angle over a spherical surface. This measurement is time consuming so it is only performed for three channels in a band in order to reduce overall measurement time. However, the whole band performance in real environments is critical in the research and development stage, and even in potential certification measurement. A novel fast band-sweep measurement for TIS of wireless devices is proposed in this paper. This method measures the radiated sensitivity and the average gain of the receiver antenna separately, and then combines them to obtain the TIS. The measurement of the radiated sensitivity in a band is efficiently performed based on the relationship between the bit error rate and the received power, and the band-sweep average gain of mobile antennas can be achieved through peak gain measurements. Hence, this method reduces band-sweep measurement time significantly and also ensues the measurement accuracy by eliminating the systematic error in the received signal strength indicator reporting.

Interpreting the Total Isotropic Sensitivity and Diversity Gain of LTE-Enabled Wireless Devices From Over-the-Air Throughput Measurements in Reverberation Chambers

The characterization of the performance of wireless devices is key to developing new RF products conforming to the latest communications protocols. Traditionally, communication performance tests have focused on the RF performance of the tested devices, e.g., smart phones, pads, laptops, and so on. In particular, the focus has shifted from conducted (i.e., cabled) measurements to more realistic over-the-air (OTA) characterization of the RF performance of these devices in transmit or receive mode. For example, the receiver performance of 2G and 3G wireless devices can be measured in terms of the total isotropic sensitivity (TIS) that depends on the antenna and the receiver parts of a wireless device. These measurements can be performed in a reverberation chamber setup. However, standard TIS measurements can be time-consuming and do not reflect the actual performance gains of multiple-input multiple-output antenna systems operating over orthogonal frequency division multiplexing channels, such as those encountered in 4G long-term evolution (LTE) systems. Therefore, in order to meet both time and cost efficiency requirements, we propose here a new method to determine the TIS, as well as the diversity performance, of an LTE device based on throughput measurements. The proposed method shows that the TIS of an LTE device is characterized much faster directly from OTA throughput measurements than from standard TIS measurements and with excellent accuracy.

FEASIBILITY STUDY OF ANTENNA INTEGRATED CAPACITIVE SENSOR IN OPERATIONAL MOBILE PHONE

An antenna integrated sensor implementation for hand or flnger proximity recognition is developed. Capacitive sensor was installed on the antenna of functional Nokia 6021 phone. The sensitivity of the phone with planar inverted F antenna (PIFA) integrated sensor was measured with active TRP (total radiated power) and TIS (total isotropic sensitivity) measurements. Phone active measurements were performed with/without data cables and compared to reference phones. Passive cable phone measurements were compared with active measurement results. TRP results had no signiflcant decrements due to integration compared with the reference phone. Some TIS channels sufiered from detrimental efiects due to interfering signals, which were measured with a spectrum analyzer.