begin cdma

cdma.Rmd

@@ -0,0 +1,40 @@
+---
+title: "CDMA"
+subtitle: "Software Defined Radio"
+output: pdf_document
+date: "`r Sys.Date()`"
+---
+# Assignment
+In the R environment for statistical computing, develop
+software support for generating a CDMA composite
+signal. Provide four parallel communication channels
+with corresponding characteristic code sequences of 5
+bits length. Define software support for accepting
+ASCII characters (via a terminal or reading from a data
+file), converting ASCII characters into binary data,
+coding with the respective code sequence of the given
+communication channel, and decoding and deciding
+on the receiving side.
+  
+```{r setup, include=FALSE}
+knitr::opts_chunk$set(echo = TRUE)
+```
+
+## Getting Input
+We first get input by reading a file `input.txt`, where each line (0-3) is one communication channel.
+Because UTF8 maintains compatibility with ASCII, the UTF8 conversion can be used assuming that the input is only ASCII.
+ASCII characters require 7 bits of information per character.
+```{r input}
+lines <- readLines('./input.txt')
+lines_bin <- unlist(lapply(lines, utf8ToInt))
+```
+
+```{r input-demo, echo=FALSE}
+print(lines)
+print(lines_bin)
+```
+
+## Orthogonal Code
+For an orthogonal code, we are looking for vectors $(a,b,...n)$ in  that satisfy pairwise orthogonality $a \perp b$.
+
+