/// Fading/AWGN Channel that operates on each sample
func (m *ChannelEmulator) FadingChannel(InCH gocomm.Complex128Channel) {
outCH := m.Pins["symbolOut"].Channel.(gocomm.Complex128Channel)
NextSize := 1
N0 := .01 /// 10dB SNR
var chdataOut gocomm.SComplex128Obj
var chdataIn gocomm.SComplex128Obj
for i := 0; i < NextSize; i++ {
chdataIn = <-InCH
sample := chdataIn.Ch
chdataOut.Message = chdataIn.Message
chdataOut.MaxExpected = chdataIn.MaxExpected
NextSize = chdataIn.MaxExpected
var hn complex128
if chdataIn.Message == "BYPASS" {
hn = 1
chdataOut.Ch = sample
} else {
hn = sources.RandNC(N0)
psample := sample * hn
chdataOut.Ch = psample
}
outCH <- chdataOut
}
}
func (m *Modem) ModulateBlock(OutBlockSize int, bitchan gocomm.BitChannel, symbolChannel gocomm.Complex128Channel) {
for i := 0; i < OutBlockSize; i++ {
var chdataIn gocomm.SBitObj
var chdataOut gocomm.SComplex128Obj
// fmt.Printf("\n MaxSymbols expected is %d , message = %v", bitchan.MaxExpected, bitchan.Message)
var bits []uint8
bits = make([]uint8, m.bitsPerSymbol)
length := m.bitsPerSymbol
N := m.bitsPerSymbol
for i := 0; i < length; i++ {
chdataIn = <-bitchan
chdataOut.MaxExpected = chdataIn.MaxExpected / 2
chdataOut.Message = chdataIn.Message
bits[i] = chdataIn.Ch
OutBlockSize = chdataIn.MaxExpected
}
key := toStr(bits[0:N])
chdataOut.Ch = m.constellationTable[key]
symbolChannel <- chdataOut
}
// close(bitchan.Ch)
}
func main() {
N := 20 /// 20 samples
L := 4 /// 5tap channel
begin := time.Now()
var cdma core.CDMA
cdma.InitializeChip()
cdma.SetSpreadCode(vlib.NewOnesC(L), true)
samples := vlib.VectorC(sources.RandNCVec(N, 1))
var data gocomm.SComplex128Obj
/// METHOD A
data.Ts = 1
data.TimeStamp = 0
data.MaxExpected = N
data.Message = ""
for i := 0; i < N; i++ {
data.Next(samples[i])
chips := cdma.SpreadFn(data)
output := cdma.DeSpreadFn(chips)
fmt.Printf("\nTxSymbol %v ", data)
// fmt.Printf("\nTx %v ", chips)
fmt.Printf("\nRxSymbol %v ", output)
}
/// METHOD B
// dataArray.MaxExpected = samples.Size()
// inCHA := gocomm.NewComplex128Channel()
// outputPin := filter.PinByID(1)
// go filter.Filter(inCHA)
// go chipset.Sink(outputPin)
// /// Actual data pushing
// for i := 0; i < N; i++ {
// dataArray.MaxExpected = N
// dataArray.Ch = samples[i]
// inCHA <- dataArray
// }
//fmt.Printf("\nFilter Residues %v", filter.FilterMemory)
// Of code
fmt.Printf("\nTime Elapsed : %v\n", time.Since(begin))
}
func (m *ChannelEmulator) AWGNChannel(dummy gocomm.Complex128Channel) {
// fmt.Printf("\n Noise ready to Input %v", dummy)
outCH := m.Pins["symbolOut"].Channel.(gocomm.Complex128Channel)
// fmt.Printf("\n Output ready to Output %v", outCH)
var chdataOut gocomm.SComplex128Obj
var chdataIn gocomm.SComplex128Obj
samples := 1
// result := make([]complex64, samples)
var StdDev float64 = math.Sqrt(m.noise * .5)
var Mean float64 = m.Mean
var noise complex128
// var noisevector vlib.VectorC
for i := 0; i < samples; i++ {
chdataIn = <-dummy
chdataOut.MaxExpected = chdataIn.MaxExpected
samples = chdataIn.MaxExpected
// fmt.Printf("\nAWGN expects %d samples @ %v", samples, dummy)
chdataOut.Message = chdataIn.Message
chdataOut.Ts = chdataIn.Ts
chdataOut.TimeStamp = chdataIn.TimeStamp
if !strings.Contains(chdataIn.Message, "BYPASS") {
if Mean == 0 && StdDev == 1 {
noise = complex128(complex(rand.NormFloat64(), rand.NormFloat64()))
} else {
noise = complex128(complex(rand.NormFloat64()*StdDev+Mean, rand.NormFloat64()*StdDev+Mean))
}
// noisevector = append(noisevector, noise)
chdataOut.Ch = chdataIn.Ch + noise
} else {
chdataOut.Ch = chdataIn.Ch
}
//fmt.Printf("\nNoise%f=%f", StdDev, noisevector)
outCH <- chdataOut
}
}
func ChannelDuplexer(InCH gocomm.Complex128Channel, OutCHA []gocomm.Complex128Channel) {
Nchanels := len(OutCHA)
var chdataIn gocomm.SComplex128Obj
var chdataOut gocomm.SComplex128Obj
NextSize := 1
for cnt := 0; cnt < NextSize; cnt++ {
chdataIn = <-InCH
data := chdataIn.Ch
NextSize = chdataIn.MaxExpected
// fmt.Printf("%d InputDuplexer : %v ", cnt, data)
for i := 0; i < Nchanels; i++ {
chdataOut.Ch = data
chdataOut.MaxExpected = NextSize
chdataOut.Message = chdataIn.Message
OutCHA[i] <- chdataOut
}
}
close(InCH)
}
func (m *Modem) DeModulateBlock(OutBlockSize int, InCH gocomm.Complex128Channel, outCH gocomm.Complex128Channel) {
var chdataIn gocomm.SComplex128Obj
var chdataOut gocomm.SComplex128Obj
for i := 0; i < OutBlockSize; i++ {
chdataIn = <-InCH
symbol := chdataIn.Ch
OutBlockSize = chdataIn.MaxExpected
bits := m.DeModulateBits(symbol)
result := complex(float64(bits[0]), float64(bits[1]))
chdataOut.Ch = result
chdataOut.MaxExpected = OutBlockSize
chdataOut.Message = chdataIn.Message
// fmt.Printf("\n Writing demod bits to %v ", outCH.Ch)
outCH <- chdataOut
}
// close(InCH.Ch)
}