As you know, easy-to-read code is not always efficient for a specific chipset. I just tried to create code as simple as possible for the readers. I haven't made any effort for effiecient code. If you think the code is not so efficient, it is 100% my fault. I haven't investigated much about verifying about the accuracy. This page is only to show you the overall logics and visualization for various LTE physical layer channels. Does every PCI allocated different RS location ? or is there any pattern or rule for RS location and PCI ? (See Reference Signal : Downlink page ) If you have the Tool Box, try with more PCI. If you compare the two examples, you would notice that the location of RS varies with PCI (NCellID). Since this is subframe 0 (NSubframe = 0), you see PSS, SSS. If you compare the two examples, you would notice that the location of RS varies with PCI (NCellID).įollowing is two example for RS display in a subframe with 25 Mhz System Bandwidth. Set(gca,'ytick', ]) įollowing is two example for RS display in a subframe with 1.4 Mhz System Bandwidth. % move the view point right on top of the plot so that it looks like plane 2D grid. First I plot 3D surface graph with the grid and I didn't find any proper functions in the toolbox to display % Following is to display the resource grid. They are not the parameter you would see in real life. % the variable pss_scale and sss_scale in this example is used only to allocate different color onto the specified % SSS first and then calculate PCI (Physical Cell ID) from the PSS,SSS. % Following is to generate and allocate PSS, SSS onto the resource grid. % by resourceGrid(indAnt0) = rsAnt0, RS symbol data is assigned to corresponding Resource Element ![]() % lteCellRSIndices(enb,0) gives you RE index (location of REs for Reference Signal). % In following lines, lteCellRS(enb,0) generate RS symbol data, % lteDLResourceGrid(enb) will give you the one subframe grid according to the specified eNB configuration. % To display anything on a OFDMA Grid, we need to create an empty grid as shown below. Now I will plot the reference signal onto radio subframe grid to give you more intuitive understanding on how the reference signal scattered over a radio frame. The bottom plot is the one that expanded the initial portion Here, you see the reference signal appears only on certain locations (specific RE number). Right side graph is the I and Q data of Reference signal plotted over resource element number of the radio frame (10 subframe/ 10 ms). Red -> real, Blue -> Imaginary') Īs you see on the left side of the graph, Cell Specifi Refence signal is a sequence data modulated in QPSK. Plot(indAnt0_arrayIndex,real(rsAnt0),'ro-',indAnt0_arrayIndex,imag(rsAnt0),'bo-') Plot(real(rsAnt0),imag(rsAnt0),'ro','MarkerFaceColor',) IndAnt0_arrayIndex = 0:length(indAnt0)-1 % lteCellRSIndices() gives you the list of RE (Resource Element) number within the whole subframe. '0' in lteCellRS(enb,0) means 'antenna port 0'. % it would give you the list of Cell Specific Reference Signal. ![]() % Then pass the eNodeB definition to lteCellRS() with a specific antenna port number, % NSubframe indicate the subframe number. % NCellID indicate PCI (Physical Channel Identity) of the Cell ![]() CellRefP = 1 means 1 transmission antenna (SISO) % CellRefP indicate number of downlink Antenna. % NDLRB indicate System Bandwith in the unit of RBs. % Since PSS is determined by each eNodeB, you have to define properites of a eNodeB. In this example, I will deal with only Cell Specific Reference signal (p0~p3, mostly p0 only for simplicify). Refer to Downlink Reference Signal page and have good understanding of various types of Reference Signal. It is confusing not only in terms of too many different types but also in terms of terminology refering to those reference signal. There are many different types of Reference Signal that may confuse a lot of people including me.
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