MODULATION SCHEME EFFICIENCY STUDY调制方案的效率研究.docVIP

RadioCommunications agency Date 23rd January 2001 Document Reference prRSWG 0101 002 0 Meeting FLCC Policy Meeting Working Paper No: RSWG(01-01)/002 Modulation scheme efficiency study Using Computer Simulation To Determine The Spectral Efficiency Of Modulation Schemes Christopher Pratt RA2 / FTSLU Abstract A study was conducted to find the relative spectral efficiency of four modulation schemes in the 38GHz band. The study was conducted by adapting a computer program to randomly place links in a sample area subject to the frequency assignment criteria laid out in RA350. The factors used to determine spectral efficiency were the maximum link density in the sample area, and the bit rate and bandwidth for each link. The report indicates that higher modulation schemes provide better spectral efficiency in both the single node and multiple node cases that were investigated. table of contents 1. Introduction 0 2. Aims and objectives 0 3. saturation simulation 0 channel data 0 link placement 0 program operation 0 4. simulation tests 0 single node simulation 0 multiple node simulation 0 placement failures vs links placed 0 5. results and analysis 0 single node simulation 0 multiple node simulation 0 placement failures vs links placed 0 6. conclusion 0 1. Introduction As the radio spectrum in the UK becomes more and more congested, there is an increasing need for more spectrally efficient links. Firstly to enable links to be assigned in places where it hitherto would not have been possible, and secondly to minimise the possible interference to future links in the surrounding area. New technological advances are allowing higher order modulation equipment to be produced – allowing higher data rates to be transmitted in bandwidth currently used for medium rate traffic. This is clearly advantageous in the case where the signal is confined in a medium where it cannot interfere with or be corrupted by other signals e.g. in the case of an optical fibre link. But the benefits