A 5-GHz fully integrated full PMOS low-phase-noise LC VCO

In this paper, we describe an original method for determining the optimal operating point of the active part (transistor) of an LC oscillator leading to the minimum phase noise for given specifications in terms of power consumption, oscillation frequency and for given devices (i.e., transistor and resonator). The key point of the proposed method is based on the use of a proper LC oscillator architecture providing a fixed loaded quality factor for different operating points of the active part within the oscillator. The feedback network of this architecture is made of an LC resonator with coupling transformers. In these conditions, we show that it is possible to easily change the operating point of the amplifier, through the determination of the turns ratio of those transformers, and observe its effect on phase noise without modifying the loaded quality factor of the resonator. The optimal operating point for minimum phase noise is then extracted from nonlinear simulations. Once this optimal behaviour of the active part known and by associating the previous LC resonator, a design of an LC oscillator or VCO with an optimal phase noise becomes possible. The conclusions of the presented simulation results have been widely used to design and implement a fully integrated, LC differential VCO on a 0.35 µm BiCMOS SiGe process.

show abstract

“…The high sensitivity of OFDM receivers to phase noise imposes a stringent constraint on the design and fabrication of oscillators and the supplementary circuitry, such that the generated phase noise level will not cause the system to fail [7]- [9]. This requirement increases the implementation cost of OFDM receivers because impairments associated with fabrication variations are usually either unpredictable or uncontrollable.…”

Section: A Prior Work On Phase Noise Compensationmentioning

confidence: 99%

“…where is related to by (9) and is related to by (7). The estimates of and from (10) will have an ambiguity of a scaling factor, which can be resolved by constraining to be 1.…”

Section: A Joint Channel and Phase Noise Estimationmentioning

confidence: 99%

Compensation of Phase Noise in OFDM Wireless Systems

Zou

Tarighat

Sayed

2007

IEEE Trans. Signal Process.

136

View full text Add to dashboard Cite

Abstract-Phase noise causes significant degradation in the performance of orthogonal frequency division multiplexing (OFDM)-based wireless communication systems. The presence of phase noise can reduce the effective signal-to-noise ratio (SNR) at the receiver, and consequently, limit the bit error rate (BER) and data rate. In this paper, the effect of phase noise on OFDM wireless systems is studied, and a compensation scheme is proposed to mitigate the common phase error and intercarrier interference (ICI) caused by phase noise. In the proposed scheme, the communication between the transmitter and receiver blocks consists of two stages. In the first stage, block-type pilot symbols are transmitted and the channel coefficients are jointly estimated with the phase noise in the time domain. In the second stage, comb-type OFDM symbols are transmitted such that the receiver can jointly estimate the data symbols and the phase noise. It is shown both by theory and computer simulations that the proposed scheme can effectively mitigate the ICI caused by phase noise and improve the BER of OFDM systems. Another benefit of the proposed scheme is that the sensitivity of OFDM receivers to phase noise can be significantly lowered, which helps simplify the oscillator and circuitry design in terms of implementation cost and power consumption.Index Terms-Common phase error, compensation scheme, equalization, intercarrier interference (ICI), orthogonal frequency division multiplexing (OFDM), performance analysis, phase-locked loop (PLL), phase noise.

show abstract

A 5-GHz fully integrated full PMOS low-phase-noise LC VCO

Cited by 60 publications

References 14 publications

Design of low power CMOS LC VCO for direct conversion transceiver

Design of low power CMOS LC VCO for direct conversion transceiver

Minimum phase noise of an LC oscillator: Determination of the optimal operating point of the active part

Compensation of Phase Noise in OFDM Wireless Systems

Contact Info

Product

Resources

About