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