/*
 * Copyright (c) 2010 TELEMATICS LAB, DEE - Politecnico di Bari
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 * Author: Giuseppe Piro  <g.piro@poliba.it>
 */

#ifndef LTE_SPECTRUM_VALUE_HELPER_H
#define LTE_SPECTRUM_VALUE_HELPER_H

#include "ns3/spectrum-value.h"

#include <map>
#include <vector>

namespace ns3
{

/**
 * @ingroup lte
 *
 * @brief This class defines all functions to create spectrum model for lte
 */
class LteSpectrumValueHelper
{
  public:
    /**
     * Calculates the carrier frequency from the E-UTRA Absolute
     * Radio Frequency Channel Number (EARFCN) according to 3GPP TS
     * 36.101 section 5.7.3 "Carrier frequency and EARFCN".
     *
     * @param earfcn the EARFCN
     *
     * @return the carrier frequency in Hz
     */
    static double GetCarrierFrequency(uint32_t earfcn);

    /**
     * Converts downlink EARFCN to corresponding LTE frequency band number.
     *
     * @param nDl the EARFCN
     *
     * @return the downlink carrier band
     */
    static uint16_t GetDownlinkCarrierBand(uint32_t nDl);

    /**
     * Converts uplink EARFCN to corresponding LTE frequency band number.
     *
     * @param nUl the EARFCN
     *
     * @return the uplink carrier band
     */
    static uint16_t GetUplinkCarrierBand(uint32_t nUl);

    /**
     * Calculates the downlink carrier frequency from the E-UTRA Absolute
     * Radio Frequency Channel Number (EARFCN) using the formula in 3GPP TS
     * 36.101 section 5.7.3 "Carrier frequency and EARFCN".
     *
     * @param earfcn the EARFCN
     *
     * @return the downlink carrier frequency in Hz
     */
    static double GetDownlinkCarrierFrequency(uint32_t earfcn);

    /**
     * Calculates the uplink carrier frequency from the E-UTRA Absolute
     * Radio Frequency Channel Number (EARFCN) using the formula in 3GPP TS
     * 36.101 section 5.7.3 "Carrier frequency and EARFCN".
     *
     * @param earfcn the EARFCN
     *
     * @return the uplink carrier frequency in Hz
     */
    static double GetUplinkCarrierFrequency(uint32_t earfcn);

    /**
     *
     *
     * @param txBandwidthConf the transmission bandwidth
     * configuration in number of resource blocks
     *
     * @return the nominal channel bandwidth in Hz as per 3GPP TS 36.101
     */
    static double GetChannelBandwidth(uint16_t txBandwidthConf);

    /**
     *
     * @param earfcn the carrier frequency (EARFCN) at which reception
     * is made
     * @param bandwidth the Transmission Bandwidth Configuration in
     * number of resource blocks
     *
     * @return the static SpectrumModel instance corresponding to the
     * given carrier frequency and transmission bandwidth
     * configuration. If such SpectrumModel does not exist, it is
     * created.
     */
    static Ptr<SpectrumModel> GetSpectrumModel(uint32_t earfcn, uint16_t bandwidth);

    /**
     * create a spectrum value representing the power spectral
     * density of a signal to be transmitted. See 3GPP TS 36.101 for
     * a definition of most of the parameters described here.
     *
     * @param earfcn the carrier frequency (EARFCN) of the transmission
     * @param bandwidth the Transmission Bandwidth Configuration in
     * number of resource blocks
     * @param powerTx the total power in dBm over the whole bandwidth
     * @param activeRbs the list of Active Resource Blocks (PRBs)
     *
     * @return a pointer to a newly allocated SpectrumValue representing the TX Power Spectral
     * Density in W/Hz for each Resource Block
     */
    static Ptr<SpectrumValue> CreateTxPowerSpectralDensity(uint32_t earfcn,
                                                           uint16_t bandwidth,
                                                           double powerTx,
                                                           std::vector<int> activeRbs);

    /**
     * create a spectrum value representing the power spectral
     * density of a signal to be transmitted. See 3GPP TS 36.101 for
     * a definition of most of the parameters described here.
     *
     * @param earfcn the carrier frequency (EARFCN) of the transmission
     * @param bandwidth the Transmission Bandwidth Configuration in
     * number of resource blocks
     * @param powerTx the total power in dBm over the whole bandwidth
     * @param powerTxMap the map of power in dBm for each RB,
     * if map contain power for RB, powerTx is not used for this RB,
     * otherwise powerTx is set for this RB
     * @param activeRbs the list of Active Resource Blocks (PRBs)
     *
     * @return a pointer to a newly allocated SpectrumValue representing the TX Power Spectral
     * Density in W/Hz for each Resource Block
     */
    static Ptr<SpectrumValue> CreateTxPowerSpectralDensity(uint32_t earfcn,
                                                           uint16_t bandwidth,
                                                           double powerTx,
                                                           std::map<int, double> powerTxMap,
                                                           std::vector<int> activeRbs);

    /**
     * create a spectrum value representing the uplink power spectral
     * density of a signal to be transmitted. See 3GPP TS 36.101 for
     * a definition of most of the parameters described here.
     * This function splits the power over the active RBs instead of
     * the entire bandwidth
     * @param earfcn the carrier frequency (EARFCN) of the transmission
     * @param bandwidth the Transmission Bandwidth Configuration in
     * number of resource blocks
     * @param powerTx the total power in dBm over the whole bandwidth
     * @param activeRbs the list of Active Resource Blocks (PRBs)
     *
     * @return a pointer to a newly allocated SpectrumValue representing the TX Power Spectral
     * Density in W/Hz for each Resource Block
     */
    static Ptr<SpectrumValue> CreateUlTxPowerSpectralDensity(uint16_t earfcn,
                                                             uint16_t bandwidth,
                                                             double powerTx,
                                                             std::vector<int> activeRbs);

    /**
     * create a SpectrumValue that models the power spectral density of AWGN
     *
     * @param earfcn the carrier frequency (EARFCN) at which reception
     * is made
     * @param bandwidth the Transmission Bandwidth Configuration in
     * number of resource blocks
     * @param noiseFigure the noise figure in dB w.r.t. a reference temperature of 290K
     *
     * @return a pointer to a newly allocated SpectrumValue representing the noise Power Spectral
     * Density in W/Hz for each Resource Block
     */
    static Ptr<SpectrumValue> CreateNoisePowerSpectralDensity(uint32_t earfcn,
                                                              uint16_t bandwidth,
                                                              double noiseFigure);

    /**
     *  create a SpectrumValue that models the power spectral density of AWGN
     *
     * @param noiseFigure  the noise figure in dB  w.r.t. a reference temperature of 290K
     * @param spectrumModel the SpectrumModel instance to be used
     *
     * @return a pointer to a newly allocated SpectrumValue representing the noise Power Spectral
     * Density in W/Hz for each Resource Block
     */
    static Ptr<SpectrumValue> CreateNoisePowerSpectralDensity(double noiseFigure,
                                                              Ptr<SpectrumModel> spectrumModel);
};

} // namespace ns3

#endif /*  LTE_SPECTRUM_VALUE_HELPER_H */
