BitVector: Remove convolutional codec - we don't use it in osmo-trx.
Now we have more fexibility in how we represent SoftVector, since we
no longer depend on the particular convolutional codec implementation.
Change-Id: I3006b6a26c5eff59dbe9c034f689961802f1d0d0
diff --git a/CommonLibs/BitVector.h b/CommonLibs/BitVector.h
index e244be7..7473c32 100644
--- a/CommonLibs/BitVector.h
+++ b/CommonLibs/BitVector.h
@@ -89,142 +89,6 @@
-
-/** Parity (CRC-type) generator and checker based on a Generator. */
-class Parity : public Generator {
-
- protected:
-
- unsigned mCodewordSize;
-
- public:
-
- Parity(uint64_t wCoefficients, unsigned wParitySize, unsigned wCodewordSize)
- :Generator(wCoefficients, wParitySize),
- mCodewordSize(wCodewordSize)
- { }
-
- /** Compute the parity word and write it into the target segment. */
- void writeParityWord(const BitVector& data, BitVector& parityWordTarget, bool invert=true);
-
- /** Compute the syndrome of a received sequence. */
- uint64_t syndrome(const BitVector& receivedCodeword);
-};
-
-
-
-
-/**
- Class to represent convolutional coders/decoders of rate 1/2, memory length 4.
- This is the "workhorse" coder for most GSM channels.
-*/
-class ViterbiR2O4 {
-
- private:
- /**name Lots of precomputed elements so the compiler can optimize like hell. */
- //@{
- /**@name Core values. */
- //@{
- static const unsigned mIRate = 2; ///< reciprocal of rate
- static const unsigned mOrder = 4; ///< memory length of generators
- //@}
- /**@name Derived values. */
- //@{
- static const unsigned mIStates = 0x01 << mOrder; ///< number of states, number of survivors
- static const uint32_t mSMask = mIStates-1; ///< survivor mask
- static const uint32_t mCMask = (mSMask<<1) | 0x01; ///< candidate mask
- static const uint32_t mOMask = (0x01<<mIRate)-1; ///< ouput mask, all iRate low bits set
- static const unsigned mNumCands = mIStates*2; ///< number of candidates to generate during branching
- static const unsigned mDeferral = 6*mOrder; ///< deferral to be used
- //@}
- //@}
-
- /** Precomputed tables. */
- //@{
- uint32_t mCoeffs[mIRate]; ///< polynomial for each generator
- uint32_t mStateTable[mIRate][2*mIStates]; ///< precomputed generator output tables
- uint32_t mGeneratorTable[2*mIStates]; ///< precomputed coder output table
- //@}
-
- public:
-
- /**
- A candidate sequence in a Viterbi decoder.
- The 32-bit state register can support a deferral of 6 with a 4th-order coder.
- */
- typedef struct candStruct {
- uint32_t iState; ///< encoder input associated with this candidate
- uint32_t oState; ///< encoder output associated with this candidate
- float cost; ///< cost (metric value), float to support soft inputs
- } vCand;
-
- /** Clear a structure. */
- void clear(vCand& v)
- {
- v.iState=0;
- v.oState=0;
- v.cost=0;
- }
-
-
- private:
-
- /**@name Survivors and candidates. */
- //@{
- vCand mSurvivors[mIStates]; ///< current survivor pool
- vCand mCandidates[2*mIStates]; ///< current candidate pool
- //@}
-
- public:
-
- unsigned iRate() const { return mIRate; }
- uint32_t cMask() const { return mCMask; }
- uint32_t stateTable(unsigned g, unsigned i) const { return mStateTable[g][i]; }
- unsigned deferral() const { return mDeferral; }
-
-
- ViterbiR2O4();
-
- /** Set all cost metrics to zero. */
- void initializeStates();
-
- /**
- Full cycle of the Viterbi algorithm: branch, metrics, prune, select.
- @return reference to minimum-cost candidate.
- */
- const vCand& step(uint32_t inSample, const float *probs, const float *iprobs);
-
- private:
-
- /** Branch survivors into new candidates. */
- void branchCandidates();
-
- /** Compute cost metrics for soft-inputs. */
- void getSoftCostMetrics(uint32_t inSample, const float *probs, const float *iprobs);
-
- /** Select survivors from the candidate set. */
- void pruneCandidates();
-
- /** Find the minimum cost survivor. */
- const vCand& minCost() const;
-
- /**
- Precompute the state tables.
- @param g Generator index 0..((1/rate)-1)
- */
- void computeStateTables(unsigned g);
-
- /**
- Precompute the generator outputs.
- mCoeffs must be defined first.
- */
- void computeGeneratorTable();
-
-};
-
-
-
-
class BitVector : public Vector<char> {
@@ -288,8 +152,6 @@
uint64_t syndrome(Generator& gen) const;
/** Calculate the parity word for the vector with the given Generator. */
uint64_t parity(Generator& gen) const;
- /** Encode the signal with the GSM rate 1/2 convolutional encoder. */
- void encode(const ViterbiR2O4& encoder, BitVector& target);
//@}
@@ -427,10 +289,7 @@
const SoftVector tail(size_t start) const { return segment(start,size()-start); }
//@}
- /** Decode soft symbols with the GSM rate-1/2 Viterbi decoder. */
- void decode(ViterbiR2O4 &decoder, BitVector& target) const;
-
- // (pat) How good is the SoftVector in the sense of the bits being solid?
+ // How good is the SoftVector in the sense of the bits being solid?
// Result of 1 is perfect and 0 means all the bits were 0.5
// If plow is non-NULL, also return the lowest energy bit.
float getEnergy(float *low=0) const;