| Abstract [eng] |
Wireless networks in world becoming more and more popular. Every year dozens of new products providing wireless access are being released. In addition to new products also new data transfer standards are created in order to exploit full radio bandwidth capabilities and improve transmission performance and security. While data transmission speed increases, radio signals become more sensitive to environmental distortions, thus increases probability that the data will be damaged due to signal interference or transmit disruption. The impact of interference can be reduced by avoiding highly occupied frequencies. Meanwhile, transmit disruptions are the different source of signal error that arises from variable hardware quality. In order to reduce the impact of this source of error device transmitter calibration is applied. After calibration, digital signals are modulated more accurately in transmitting side and successfully received demodulated on receiving side even if signals were affected by environment factors. There are many methods of measuring and evaluating digital signal quality in the world. These digital signal measures are applied while transmitter power calibration is performed. Wireless standard IEEE 802.11n specifies strict requirements for transmitting digital signal quality, however calibration procedure is not standardized. Since radio transmitter calibration is hardware dependent operation, most of system on the chip manufacturers have their own product calibration procedures and implementations. Company, Wilibox engaged in the production of wireless routers. Wireless routers that are being developed in the company uses system on the chips of different manufacturers. This impose using multiple calibration systems for each system on chip. Therefore to unify calibration procedures and calibration results new transmitter calibration system is being created to suffice companies internal requirements. Implemented system uses my own suggested EVM measuring and transmitter calibration methods. These methods performs key measure functions and therefore those methods results affects whole calibration process. In order to ensure those methods correct operability the research is being done to evaluate validity and reliability of suggested methods results. |
