A compensation scheme to allow full duplex operation in the presence of highly nonlinear microwave components for 4 G systems

Digital Suppression of Transmitter Leakage in FDD RF Transceivers: Aliasing Elimination and Model Selection

“…Furthermore, with the low sampling rate, the digital circuits can be operated at a low clock rate which can lead to significant reduction of power consumption of the circuits. In this section, we compare our approach with the solution proposed in [9], called the conventional approach, in terms of hardware resource utilization and power consumption to illustrate the benefits of the proposed solution.…”

“…22. In the conventional approach [9], the input samples were interpolated by 6 times from 61.44 MSPS to the full-rate of 368.64 MSPS and then fed into the suppression model. The aliasing-free sideband replica was then generated and down-sampled to match the leakage data rate at the output.…”

“…Due to a nonlinear process involved, the sampling rate must be set high enough during the signal generation to avoid aliasing effect. For instance, in [9], a sampling rate at 12 times input signal bandwidth was used. In [17], the signal was sampled with a sampling rate of 13 times input bandwidth.…”

Digital Suppression of Transmitter Leakage in FDD RF Transceivers With an Enhanced Low-Sampling Rate Behavioral Model

“…The filter in duplexer can suppress the transmitter (TX) leakage to some extent, but the residual leakage can still affect the received signal if the leakage power is high. Digital suppression [1] [2] has been considered as an effective technique to mitigate TX leakages. It applies a digital model to regenerate the leakage replica and then subtracts it from the received signal.…”

Digital Compensation for Transmitter Leakage in Non-Contiguous Carrier Aggregation Applications With FPGA Implementation

“…In [13], M. Kahrizi et al proposed a digital method to suppress the second-order intermodulation (IM2) of Tx leakage in WCDMA direct-conversion receivers. M. Omer et al in [14] created the replica of the sideband distortion by assuming that the frequency response of duplex filter is known, while A. Kiayani et al in [17] proposed a method to estimate the transmitter leakage channel including both duplexer and PA.…”