Local Oscillator Phase Noise Influence on Single Carrier and OFDM Modulations

Abstract

Abstract. This paper describes the influence of local oscillator phase noise on single and multi-carrier modulations schemes. The oscillator has the main role on modulation and demodulation process of the radio frequency channels. The synchronization of the entire system depends on the accuracy of this circuit. This work is based on the simulation of these two scenarios under influence of a non-ideal oscillator. The output of the simulation scenario results of error vector magnitude, bit error rate and symbol error rate. The relation of these metrics with the local oscillator phase noise allows the performance estimation the global system. A simple phase noise model is presented with configurable power spectral density and offset frequency.

RF Synthesizer Loop Filter Design for Minimal OFDM Inter-carrier Interference

“…Unlike single carrier systems [11], [12], OFDM spectral content does not present a direct relation with phase noise, due to information split through the several subchannels, the CP insertion and raised-cosine windowing. To obtain a significant result based on spectrum analysis, it is necessary to cancel the analyzed sub-channel, extracting the noise mean power within its bandwidth.…”

“…The transmitted data stream is mapped into 16-QAM with configurable symbol frequency. The IFFT and FFT use 64 points [11] and the cyclic prefix contains 16 extra samples per symbol. OFDM symbol windowing is a square-root raised cosine filter.…”

“…4, allows the configuration of the integrated phase noise power and bandwidth. Previous works show how phase noise power distribution affects single carrier [12] and OFDM [11] modulation schemes. In this work, it is possible to predict the noise power within an OFDM sub-channel under several phase noise masks for a specific synthesizer loop filter topology.…”

“…The main contribution and novelty of this work consists on performing phase noise shaping without changing the LO characteristics. The validation of the proposed work is based on OFDM simulation scenario with configurable RF parameters [11], which enables the extraction of inter-carrier interference (ICI) for several loop filter topologies.…”

Hybrid Precoding for Millimeter Wave Systems under Phase Noise problem

“…One of this two input ports is usually the local oscillator (LO) device, it is one of the main components of radio frequency system, which in charge of the (up/down) conversion of a particular channel. In detail, it has the most important role on modulation and demodulation processes [8].…”