Research And Design Lte Multimode Receiver Front-end

With the exploding development of wireless communication and the growing demand for high speed and feature-rich devices, Long-Term-Evolution (LTE) becomes the necessary transition technology from3G to4G. With the low cost and low power for consumer electronics, multi-mode and high performance transceiver becomes the hot topic for academy and industry area. With the design targeting of TDD LTE, the main content of this work includes:First, this work explores performance of the receiver front-end required by communication standard, and analyzes the specification under various modes, and also validates the results by system simulation. Based on the reconfiguration flexibility requirement and the no DC component within the modulated signal, direct conversion architecture is chosen for reconfigurable multi-mode LTE receiver. The specification allocation for each block in the receiver chain is optimized for high performance and low power design under low power supply voltage, and gives valuable reference for circuit level design.Second, taking the advantage of the scaling down CMOS process, a wideband receiver RF front-end for SDR application is realized in this work. A novel resistive feedback wideband low-noise-amplifier with feedforward noise cancellation is also designed for this front-end. Both calculation and experimental results validate the proposed structure improves the voltage gain, NF and IIP3without extra power consumption. A current commutating mixer and tunable bandwidth2nd order TIA is also realized in this design, providing effective attenuation for out of band interference and relaxing the linearity requirement for the following stages, which provides a feasible solution for gain allocation and high dynamic range with low power supply design. The experimental results of the wideband RF front-end satisfy the specification and achieves advanced level in this area.Third, A TDD LTE multi-mode automatic tuned narrowband receiver front-end is innovatively realized in this work. A automatic tuning loop is invented for low-noise-amplifier tuning to cover the1.88-2.62GHz frequency range, and also calibrates the PVT variation. Current commutating passive mixer, pre-amplifier, tunable bandwidth channel selection filter and PGA are also included in this receiver chain. All the digital assisted reconfiguration is downloaded by digital interface for reconfiguration flexibility. Simulation and measurement results satisfy the system specification. Compared with the reported literatures, this chip provides more flexible re-configuration and occupies less chip area.Finally, an ultra wideband receiver is designed with the combination of wideband and tunable narrowband RF front-end. Digital configuration is used for choosing the wideband front-end that covers the low band and tunable narrowband front-end that covers the high band. It can cover the500MHz-2.8GHz, which covers most of the wireless communication standards such as GSM/TD-SCDMA/WCDMA/WLAN/LTE.