Software defined solution for hardware imperfections in MIMO transmission | May 2015 to May 2016
Communication | Electronics and Communication Engineering Department

This is the dissertation work of M.Tech it includes implementation of digital pre-distortion techniques and modelling algorithms with the consideration of equalization for single-input-single output transceivers and impact of diversity in multiple-input-multiple-output transceivers. A joint method for compensation of power amplifier non-linearity and diversity implementation is proposed for the case multiple-input-multiple-output transmitters.

Low cost implementation of Software Defined Radio for improved transmit quality of 4G signals | 2015
in Proc. IEEE Int. Conf. on Commun. Control and Intelligent syst., (CCIS-2015), Mathura | G. C. Tripathi, P. Jaraut, M. Rawat and L. N. Reddy

This paper presents the development and
implementation of digital pre-distortion algorithm for a low cost FPGA based platform.

Digital Predistortion of Power Amplifiers with Diversity Technique in 4G MIMO Transceivers | 2015
in Proc. IEEE MTTS Int. Microw. and RF Conf., (IMaRC), Hyderabad, India, | G. C. Tripathi, P. Jaraut, M. Rawat and L. N. Reddy

This paper presents the practical implementation
of digital predistortion (DPD) for power amplifier along with the
transmitter and receiver diversity techniques for multiple inputs
multiple outputs (MIMO) communication to enhance channel
capacity and increased coverage.

Linearization of traveling-wave tube amplifiers using digitally supported signal injection technique | 2017
Journal of Electromagnetic Waves and Applications, Taylor and Francis | G. C. Tripathi, Meenakshi Rawat, Sudhir Kamath, and M. V. Kartikeyan

This paper presents a digitally supported signal injection technique for the intermodulation distortion terms (IMDs) resulting from the non-linearity of Traveling-wave tube amplifiers. It is shown that the state-of-the art analog techniques have inherent limitation due to the inaccuracy of analog components. The proposed technique provides more accurate cancellation of third-order IMD as compared to its analog counterpart. Moreover, it is shown that the presented technique can be easily extended to compensate for higher order IMDs simultaneously.

Delay compensation for 4G/5G Transmitter System Characterization | 2017
Microwave and Optical Technology Letters Wiley publication | G. C. Tripathi, Meenakshi Rawat

The 4G and 5G communication system propose and anticipate signals, algorithms, or schemes such as carrier aggregation to provide better data rate and bandwidth requirements. To fulfil such requirements, there is a need to represent the transmitter accurately in simulation scenario to observe the impact of new algorithms on system level. The transmitter system characterization requires modeling of relation between input and output signals. However, there is a delay between transmitted and received signal which needs to be compensated. This letter proposes a modified frequency domain time delay compensation technique, which is more effective in estimating the time delay in case of carrier aggregated signals composed of multiple widely spaced component carriers. It has been tested on a software defined radio platform which can also be used for transmitter modeling. Significant improvement of 4 dB approximately in the term of normalized mean square error between transmitted and received signal has been reported.