ofdm_defines.h

DSP 5409 plc应用程序,调试通过,是用在电力线通讯上的演示程序.

/*========================================================================
 Filename:                                     ofdm_defines.h

 Description:  This file contains the #define constants used in the OFDM power line modem.
               It is generated by saving the excel spreadsheet ofdm_defines.xls as an unformated text file.
               In the spreadsheet, bold values are direct entries, non-bold values are calculated.

 Copyright (C) 2002 - 2003 Texas Instruments Incorporated
 Texas Instruments Proprietary Information
 Use subject to terms and conditions of TI Software License Agreement

 Revision History:
==========================================================================*/
#ifndef        OFDM_DEFINES_H                                      // Header file guard
#define        OFDM_DEFINES_H

#define        VERSION                             20030513        // id the parameters

//---- Word size ---------------------------------
#define        BYTE_LEN                                   8
#define        WORD_LEN                                  16
#define        BYTE_MSB                            0x0080U
#define        WORD_MSB                            0x8000U

//---- Modem characteristics ---------------------------------
//             cyclic prefix time                      0.25msec
#define        FFT_LEN                                  256        // length of IFFT/FFT OFDM field
#define        CYCLIC_PREFIX_LEN                         42        // # of samples in cyclic prefix                   64
#define        WINDOW_LEN                                16        // # of windowed samples in cyclic prefix
#define        SYNC_FIELD_LEN                           384        // # samples in sync field
#define        NUM_PRE_FRAMES                             8        // # pf frames in preamble
#define        NUM_USER_BYTES                           128        // # of user bytes in packet

#define        WAVE_ZERO_PAD_FRONT                      800        // # of zeros to pad simulated transmit waveform (Matab only)
#define        WAVE_ZERO_PAD_BACK                       500        // # of zeros to pad simulated transmit waveform (Matab only)

//---- get carrier frequency bins  -----------------------------
//             DSP sample rate (Fs)                     250k                                                         250
//             lowest allowable carrier freq             48k                                                          48       9
//             highest allowable carrier freq            88k                                                          88      94
//             frequency resolution                     1.0k
//             carrrier range as % of Fs             19.14%  34.38%
#define        CARRIER_LOW                               51        // ((CARRIER_FREQ_LOW * FFT_LEN) + SAMPLE_FREQ-1) / SAMPLE_FREQ
#define        CARRIER_HIGH                              90        // (CARRIER_FREQ_HIGH * FFT_LEN) / SAMPLE_FREQ
#define        CARRIER_LEN                               40        // CARRIER_HIGH - CARRIER_LOW + 1

//---- calc the number of bits to send in the packet ----------------------------
//             total un-encoded bytes                   131        userBytes + crcBytes + viterbiPadByte
//             total bits                              1048        8 bit bytes
//             num encoded bits                        2096        total bits / rate
//             num bits / frame                          80        bits
//             AFE_SIZE                                   3        words
//             RX_SRC_INC                                 2        words
#define        NUM_DATA_BLOCKS                           27        // CEILING(num_encoded_bits/num_bits_per_frame)
#define        NUM_SYMBOLS                             1080        // total number of symbols in message

#define        DATA_FRAMES_PER_BLOCK                      3        // # of time to repeat each frame
#define        SYMBOL_OFFSET                             15        // shift each symbol this much from frame to frame in a block

#define        DATA_BUFFER_LEN                           68        // words = NUM_SYMBOLS*BITS_PER_SYMBOL*encoder_rate/WORD_LEN

//             preamble+sync length                    2560        NUM_PRE_FRAMES*FFT_LEN + SYNC_FIELD_LEN
//             data field length                      24154        NUM_DATA_FRAMES*(CYCLIC_PREFIX_LEN + FFT_LEN) + WINDOW_LEN
//             receive waveform in Matlab:            28014
//             number of receive buffer frames            8
#if            COMPILE_MODE == MEX_COMPILE
       #define TX_BUFFER_LEN                          26714L       // samples = preamble + data
       #define RX_CIRC_BUFFER_LEN                     32768L       // size of receiver circular buffer
#else          // DSP_COMPILE
       #define TX_BUFFER_LEN                            894L       // samples = preamble + data
	#ifdef _C5410
		#define RX_CIRC_BUFFER_LEN                     16256L       // Maximum space available for receive circular buffer
	#else
		#define RX_CIRC_BUFFER_LEN                     7680L       // Size of receive circuluar buffer (max room in 5409
	#endif
#endif

//---- CRC and scrambler ------------------------------------------
#define        SCRAMBLER_LEN                            127        // order 7 polynomial

#define        CRC_LEN                                   16        // length in bits of CRC word
#define        CRC_POLYNOMIAL                       0x8005         // generator polynomial
#define        CRC_TOPBIT                           0x8000         // MSB
#define        CRC_REG_INIT                         0xFFFF         // initial value for control register
#define        CRC_BLOCK_LEN                             16        // num bytes over which to calc a CRC word

//---- Convolutional encode/decode parameters -------------------------------
//             encoder_rate                             0.5

#define        VITERBI_K                                  7        // length of encoder
#define        VITERBI_NUM_STATES                        64        // number of states in trellis
#define        VITERBI_MEM_LEN                           32        // length of shift reg in bits
#define        VITERBI_MSB                     0x80000000U         // mask for MSB of 32bit word
#define        VITERBI_LSB                     0x00000001U         // mask for LSB of 32bit word
#define        VITERBI_CAR1_RE                          200        // inital value for previous carrier1 for frame0
#define        VITERBI_CAR1_IM                            0

#define        VITERBI_ENCODE_SHIFT                       9        // shift data bit from MSB to bit 7 of state
#define        VITERBI_DISTANCE_SHIFT                    17        // scale the distance metric for a branch

//---- modulation parameters ---------------------------------------------
#define        BITS_PER_SYMBOL                            2        // number of bits per symbol

#if            COMPILE_MODE == MEX_COMPILE
       #define PRE_IFFT_SCALE                            14        // shift ifft data left this many bits
       #define DATA_IFFT_SCALE                           14        // same deal
       #define IMP_IFFT_SCALE                             1        // shift carrier left this much when calc'ing impulse resp

       #define IFFT_SCALE                                 0        // scale FFT output by 1/FFT_LEN or not
       #define FFT_SCALE                                  1        // scale FFT output by 1/FFT_LEN

#else          //     DSP_COMPILE
       #define PRE_IFFT_SCALE                             8        // shift ifft data left this many bits
       #define DATA_IFFT_SCALE                            8        // same deal
       #define IMP_IFFT_SCALE                            -4        // shift carrier left this much when calc'ing impulse resp

       #define IFFT_SCALE                                 0        // scale FFT output by 1/FFT_LEN or not
       #define FFT_SCALE                                  1        // scale FFT output by 1/FFT_LEN
#endif

//---- AGC parameters --------------------------------------------------------------
//             initial register value                     7

#define        AGC_INTERVAL                              16        // Get interupted every n samples and calc new AGC gain
#define        NUM_ALIGN_FRAMES                           5        // # of frames to ave to do frame align
#define        FFT_LEN_SHORT                             64        // samples for short FFT

#define        ADC_CLIP_LEVEL                        0x7FFF        // modeled 13bit ADC clip level
#define        ADC_READ_SHIFT                             2        // Amount to shift read-in word

#define        AGC_CTRL_MAX                               7        // max AFE1230 RXPGA register value
#define        AGC_CTRL_MIN                               0        // min AFE1230 RXPGA register value
#define        AGC_CTRL_SHIFT                            10        // amount to right shift AGC control gain
#define        AGC_CTRL_HALF                            512        // Add to control var to correct for trunc after shift

#define        AGC_THRS_LO_IDLE                     0x1500         // 16.4%
#define        AGC_THRS_HI_IDLE                     0x3000         // 37.5%
#define        AGC_THRS_LO_PRE                      0x2000         // 25.0%
#define        AGC_THRS_HI_PRE                      0x4000         // 50.0%
#define        AGC_INIT_GAIN                           7168        // initial log agc gain

#define        AGC_OVERFLOW_COUNT                       300        // allow this many overflows per packet

//---- Packet Detect parameters -------------------------------------------------------------
//             double difference phase high thr         47%        // Do an fft every n samples to see if its preamble
//                                           lo         20%        // Do an fft every n samples to see if its preamble
//             FFT measurements per frame                 4        // Do an fft every n samples to see if its preamble
#define        SNR_FFT_INTERVAL                          64

#define        SNR_PRE_DET_COUNT                          4        // # of fft intervals to see before holding

#define        DDPHASE_MSHIFT                             8        // double-difference phase calc scale
#define        DDPHASE_HI_LIM                            38        // upper and lower thresholds for preamble detect
#define        DDPHASE_LO_LIM                            16        //

//---- Frame Align parameters --------------------------------------------------------------
//             Align done % of CARRIER_LEN              55%        //
#define        PHASE_MEAS_LEN                             5        // number of subcarriers to use to compare phase
#define        ALIGN_DONE_CRITERIA                       22        // Criteria for desiding if we've run into the sync field
#define        WORST_PWR_LIMIT                           33        // check for low SNR

#define        PWR_SCALE_SHIFT                           10        // num fraction bits
#define        CARRIER_SCALE                             13        // num fraction bits
#define        PWR_SHIFT                                 10        // num fraction bits
#define        FEQ_SHIFT                                  8        // num fraction bits

#endif          // OFDM_MODEM_CONST_H                                 Header file guard