| As wireless communication technology develops rapidly and the increasingrequirement from consumers, GSM and WCDMA terminals are already cannot satisfypeople’s demand for high speed data transmission. To resolve this issue,3GPP putforward the Long-term Evolution plan at the end of2004after discussion. TheLong-term Evolution, short for LTE, not only improves the air interface technology of3G networks but also makes it possible for the peak rate of data transmission to reach100MBPS for downlink and50MBPS for uplink.For the domestic LTE terminals, they are unifunctional and types are limited.Besides, their prices are very high in overall, especially the one support TD-LTE.Therefore developing a more reliable and cheap TD-LTE terminals has become themain direction for LTE carrier and terminal manufactures. However, there are fewpapers in terminal design and performance test area, and even less in the RF circuitsystem design and testing. In view of the above situation, this paper successfullydesigned a TD-LTE terminal with RF circuits, and calibrated it with a comprehensivetest.First of all, this paper briefly introduces several key techniques used in LTEsystem. Then it illustrates the structure of different RF transceiver system and theirrespective advantages and disadvantages. Thirdly, it detailed describes the wholeprocess of the RF circuit design based on Qualcomm9200platform, including both thelaunching circuit and receiving circuit. After this, it realizes an RF calibration for thedata card according to the3GPP requirements. In the last, it presents the results andconcludes that this TD-LTE terminal completely satisfy the requirements of the3GPPprotocol. |
