QPSK BER simulation in Golang

qpskber.go

package main

import (
 "fmt"
 "math/rand"
 "math"
 "io/ioutil"
 "time"
 "flag"
 "runtime"
)

var concflag *bool = flag.Bool("conc", true, "#Enables Concurrent Goroutines Default [true]")
var randomize *bool = flag.Bool("randomize", false, "#Randomize Seed ")

func main(){
 
 
 flag.Parse()
 flag.PrintDefaults() 
 if *randomize{
  rand.Seed(time.Now().UnixNano()) 
 }
 
 concurrent:=*concflag
 fmt.Printf("\nMax Available CPUS %v",runtime.NumCPU())  
 fmt.Printf("\nCurrent SET CPUS %v",runtime.GOMAXPROCS(-1))
 
 t:=time.Now()
 fmt.Printf("\nTime Now : %v",t)
 snr,ber:=simulate(20,concurrent)
 fmt.Printf("\nElapsed : %v",time.Since(t))
 fmt.Printf("\n With Concurrent : %v",concurrent)
 fmt.Printf("\n SNR = %v",snr)
 fmt.Printf("\n BER = %v",ber)
 towrite:=false
 if(towrite){
  var txttowrite =fmt.Sprintf("snr =%v\n",snr)+fmt.Sprintf("ber =%v\n",ber)
  ioutil.WriteFile("results.m",[]byte(txttowrite),0600)
  
 }
 
 
 fmt.Printf("\n Done..\n")
}



func simulate(n int,runtype bool) (snrdB []float64,ber []float64) {
 var f=make([]float64, n) 
 var snr=make([]float64, n)
 var initSNR float64
 initSNR= 0
 
 if runtype{
  
  ch := make(chan float64,20) 
  
  
  for k := 0; k < n; k++ {
   var currentSNR=initSNR+float64(k)
   snr[k]=currentSNR
   go link(ch, float64(currentSNR)) 
  }
  for k := 0; k < n; k++ {
   f[k] = <-ch
  }
  
} else {
 for k := 0; k < n; k++ {
  var currentSNR=initSNR+float64(k)
  snr[k]=currentSNR
  f[k]=seqlink(currentSNR)   
 }
 
}

return snr,f
}

func link(ch chan float64, k float64) {
 Nbits:=1024*100 //*(50-int(k))
 var symbols=[]complex128{0.7+0.7i,+0.7-0.7i,-0.7+0.7i,-0.7-0.7i}
 
 var txbits=make([]int,Nbits)
 for i:=0;i<len(txbits);i++{
  txbits[i]=rand.Intn(4)
 }
 
 var txsymbols=make([]complex128,Nbits)
 var noise=make([]complex128,Nbits)
 var rxnoise=make([]complex128,Nbits)
 var noisevar float64
   
 lsnr:=float64(math.Pow(10,(k/10)))
 Es:=float64(1)
 noisevar=Es/lsnr
 errorbits:=int(0)
 for i,indx :=range txbits{
  txsymbols[i]=symbols[indx]   
  noise[i]=complex(rand.NormFloat64()*math.Sqrt(noisevar*0.5),rand.NormFloat64()*math.Sqrt(noisevar*0.5))
  tmp:=txsymbols[i]+noise[i]
  
  switch
  {
   case real(tmp)>0 && imag(tmp)>0:rxnoise[i]=symbols[0]
   case real(tmp)>0 && imag(tmp)<0:rxnoise[i]=symbols[1] 
   case real(tmp)<0 && imag(tmp)>0:rxnoise[i]=symbols[2] 
   case real(tmp)<0 && imag(tmp)<0:rxnoise[i]=symbols[3] 
  } 
  if (rxnoise[i]!=txsymbols[i]){
   errorbits++   
  }
 
 }
 var ber =float64(errorbits)/float64(Nbits) 
 ch <- ber
}

func seqlink(k float64) float64 {
 Nbits:=1024*100 //*(50-int(k))
 var symbols=[]complex128{0.7+0.7i,+0.7-0.7i,-0.7+0.7i,-0.7-0.7i}
 
 var txbits=make([]int,Nbits)
 for i:=0;i<len(txbits);i++{
  txbits[i]=rand.Intn(4)
 }
 
 var txsymbols=make([]complex128,Nbits)
 var noise=make([]complex128,Nbits)
 var rxnoise=make([]complex128,Nbits)
 var noisevar float64
   
 lsnr:=float64(math.Pow(10,(k/10)))
 Es:=float64(1)
 noisevar=Es/lsnr
 errorbits:=int(0)
 for i,indx :=range txbits{
  txsymbols[i]=symbols[indx]   
  noise[i]=complex(rand.NormFloat64()*math.Sqrt(noisevar*0.5),rand.NormFloat64()*math.Sqrt(noisevar*0.5))
  tmp:=txsymbols[i]+noise[i]
  
  switch
  {
   case real(tmp)>0 && imag(tmp)>0:rxnoise[i]=symbols[0]
   case real(tmp)>0 && imag(tmp)<0:rxnoise[i]=symbols[1] 
   case real(tmp)<0 && imag(tmp)>0:rxnoise[i]=symbols[2] 
   case real(tmp)<0 && imag(tmp)<0:rxnoise[i]=symbols[3] 
  } 
  if (rxnoise[i]!=txsymbols[i]){
   errorbits++   
  }
 }
 var ber =float64(errorbits)/float64(Nbits)
 return ber
}