This article presents a comprehensive survey of the literature on self-interference (SI) in long-term evolution advanced (LTE-A) and fifth-generation (5G) new radio transceivers and should serve the reader as a guide and starting point for further work on SI management. Current trends in cellular transceiver designs are discussed, and reasons why new technologies, such as carrier aggregation, cause potential sensitivity degradation due to self-interfering signals are highlighted. The survey provides an overview of the most common interference mechanisms and continues with a taxonomy on SI mitigation architectures by comparing the strengths and weaknesses of various techniques.

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A Survey of Self-Interference in LTE-Advanced and 5G New Radio Wireless Transceivers

We present a highly configurable, low-power, low-area, low-EVM, SAW-less transmitter (TX) architecture that is based on a dynamically biased power mixer. All FDD/TDD bands from 0.7 to 2.7 GHz for 4G LTE Rel-11 and 3G $\bf{HSPA} + $ are supported in addition to 2G quad bands. The power-mixer bias current is dynamically adjusted based on the instantaneous baseband signal swing using a fully-differential hybrid full-wave rectifier/envelope-detector circuit. Dynamic biasing leads to greater than 50% current savings when compared to fixed-biasing while providing a higher output power with better linearity. Implemented in 28 nm CMOS technology, the TX shows better than $- \bf{157}\;\bf{dBc}/\bf{Hz}$ RX-band noise emission and $- \bf{41}\;\bf{dBc}$ ACLR for output powers up-to $+ \bf{4}\;\bf{dBm}$ across all 3G/4G bands, while demonstrating above 80 dB of gain control range. In addition, the TX can be configured to provide better than $- \bf{65}\;\bf{dBc}$ CIM3, allowing it to meet stringent spurious emission specifications when transmitting 1 RB 4G LTE signals in B13/B26/B1.

A Dynamically Biased Multiband 2G/3G/4G Cellular Transmitter in 28 nm CMOS

Multimode cellular RFICs need high dynamic range in order to simultaneously satisfy the high linearity requirements of LTE and the low-noise performance of 2G. Traditionally, SAW filters are employed to relax the noise-linearity trade-off at the cost of higher BOM. In a highly competitive market, mobile devices need to support >35 LTE bands, a number which is expected to rise further in the future, providing a strong motivation for SAW-less transmitter (TX) design. An LTE TX operating in the single resource-block (RB) mode is susceptible to spurious out-of-band (OOB) emission due to the high power spectral density concentrated in narrow bandwidths at frequency offsets as large as 4.5MHz (LTE10) or 9MHz (LTE20) from the carrier [1]. The most challenging condition is for B13 where the 3rd-order counter intermodulation (CIM3) product falls in an adjacent public-safety band. With 23dBm at the antenna, a B13-TX must ensure OOB emission less than −57dBm/6.25kHz in the public safety band.

13.3 A SAW-less reconfigurable multimode transmitter with a voltage-mode harmonic-reject mixer in 14nm FinFET CMOS

A novel triple-path PLL (TPPLL) is presented to compensate the VCO frequency drift caused by the large temperature variations meanwhile maintaining a stable bandwidth and good jitter performance The proposed PLL architecture splits the VCO tuning loop into three paths as the proportional, the integral, and the temperature compensation (TC) path, respectively The feed-forward TC path with a large VCO gain but a small bandwidth is adopted to realize the compensation for the VCO frequency temperature drift in a closed-loop manner without affecting the high-frequency performance of the VCO The fixed control voltage on the proportional path and limited control-voltage variation on the integral path desensitize the VCO gain ( $K_{\mathrm {VCO}}$ ) non-linearity and stabilizes the loop bandwidth over large temperature range The small VCO gain on the proportional and integral paths contributes to low phase noise and spurs In addition, the different gain settings for the separate proportional and integral paths work as a capacitor multiplier, leading to saving on the silicon area of the loop filter A prototype TPPLL at 256 GHz using a 65-nm CMOS process has been implemented and measured The core circuits occupy an area of 008 mm2, and consume 85 mW The silicon measurement results show that this PLL can continuously work (without calibration) when the temperature changes from 300 K down to 77 K, and has a frequency drift reduction by 99%, while keeping good jitter performance across the entire temperature range

A Temperature Compensated Triple-Path PLL With $K_{\mathrm {VCO}}$ Non-Linearity Desensitization Capable of Operating at 77 K

This paper presents a wideband linear direct-digital RF modulator (DDRM) in 40-nm CMOS technology. An innovative $I/Q$ -interleaving RF digital-to-analog converter (DAC) is proposed to enable the combination of in-phase ( $I$ ) and quadrature ( $Q$ ) signals in a more digital fashion, thereby improving the linearity performance at large bandwidths. The DDRM also features an advanced second-order hold digital interpolation filter to suppress the sampling spectral replicas in the presence of large bandwidth signals. Moreover, the harmonic rejection technique in the context of RF DAC operation is adopted and implemented. The $2 \times 9$ -bit DDRM core occupies 0.21 mm2 and consumes 110 and 146 mW at 1 and 3 GHz, respectively, with the peak power of +9.2 dBm. The error vector magnitude (EVM) and adjacent channel power ratio (ACPR) at 3 GHz for a 57-MHz 64-QAM signal are better than −30 and −45 dB, respectively, and ACPR remains as low as −44 dBc up to a wide bandwidth of 113 MHz.

A Wideband Linear $I/Q$ -Interleaving DDRM

Carrier aggregation is a key feature of the 3GPP LTE-Advanced cellular network standard that combines multiple channels to support higher data rates and improve the utilization of fragmented spectrum holdings. This work presents a cellular transmitter capable of transmitting a maximum of four channels simultaneously, two contiguous channels in two bands, with an aggregate bandwidth of up to 80 MHz, supporting a 200 Mbps uplink rate. The transmitter has 8 RF output ports covering the cellular transmit bands within the 572–2025 MHz frequency range. It can support LTE-Advanced Release 12 Cat7, $\text{HSPA} + \text{Release} 11$ , TDSCDMA Release 9, and GSM/EDGE Release 9. The 40 nm CMOS transmitter consumes 22 mA and 27 mA in 3G and LTE modes (at 0 dBm antenna power), respectively, including the PLL, DCXO, and biasing for a single channel.

A Rel-12 2G/3G/LTE-Advanced 2CC Transmitter

A new LC-tank VCO to minimize frequency drift due to temperature variations for cellular applications is presented. By employing the feed-forward VCO gain multiplication technique, frequency drift is reduced by 83% without resorting to conventional temperature dependent biases and circuits. Additionally, the compensation circuit retains the original VCO behavior with no degradation in performance. A fractional-N PLL fabricated in 40 nm CMOS shows that the VCO draws 9 mA and the temperature compensation circuit draws 200 µA. Measurements show that the VCO has a tuning range of 46% (from 2890 MHz to 4560 MHz) and a phase noise of −102 dBc/Hz at 200 kHz offset centered at 3960 MHz at the PLL output before the divide-by-two circuit for 3G/LTE Band I.

A temperature compensated VCO using feed-forward gain multiplication for cellular applications

This work presents a cellular transceiver capable of transmitting two simultaneous channels with an aggregate bandwidth of up to 40 MHz, supporting a 100 Mbps uplink rate. The transmitter has 8 RF output ports covering the cellular transmit bands within the 572–2100 MHz frequency range. It can support TX LTE-advanced Rel-12 Cat7, HSPA+ Rel-11, TDSCDMA Rel-9, and GSM/EDGE Rel-9. The 40 nm CMOS transmitter consumes 22 mA and 27 mA in 3G and LTE modes (at 0 dBm antenna power), respectively, including the PLL, DCXO and biasing for a single channel.

Sining Zhou

Papers

A Rel-12 2G/3G/LTE-Advanced 2CC Transmitter

A temperature compensated VCO using feed-forward gain multiplication for cellular applications

A Rel-12 2G/3G/LTE-advanced 2CC transmitter