Changes between Version 8 and Version 9 of OFDM/MIMO/Docs/ModelSharedMem


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Timestamp:
Jan 26, 2008, 1:50:33 AM (16 years ago)
Author:
murphpo
Comment:

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  • OFDM/MIMO/Docs/ModelSharedMem

    v8 v9  
    88The current version of the OFDM core requires the modulation schemes to be pre-programmed at both the transmitterand receiver. A future revision will include the ability to communicate this information with the header of each packet.
    99
    10 The transmitter and receiver sections of the core have separate modulation selection memory blocks. The organization of these two memory blocks are identical. The C-code below illustrates the memory organization and how user-code can write to these memory blocks. The macros ''ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET'' and ''ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET'' represent the address offsets (relative to the OFDM core's base address) for the two memory blocks. These macros are defined in the OFDM core's driver ([source:/PlatformSupport/CustomPeripherals/drivers/ofdm_TxRx_mimo_opbw_v1_07_a/src/ofdm_TxRx_mimo.h@L#L141 ofdm_TxRx_mimo.h]).
     10The transmitter and receiver sections of the core have separate modulation selection memory blocks. The organization of these two memory blocks are identical. The C-code below illustrates the memory organization and how user-code can write to these memory blocks. The macros ''ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET'' and ''ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET'' represent the address offsets (relative to the OFDM core's base address) for the two memory blocks. These macros are defined in the OFDM core's header file, generated by sysgen2opb.
    1111
    12 {{{
    13 #!c
    14 void setModuation()
    15 {
    16         //The following modulation schemes match the 802.11a/g standard
    17         // Each places data on 48 subcarriers
    18         // Zeros are inserted at the remaining 16 subcarriers:
    19         //   Subcarrier 0 (DC) must always be zero
    20         //   Subcarriers 7, 21, -7, -21 are used for pilot tones (i.e. zero data)
    21         //   Subcarriers [27:31] and [-32:-27] are zero to meet spectral mask requirements
     12Please see the warpphy_set_modulation() function in [source:/PlatformSupport/WARPMAC/warpphy.c] for the C code which writes modulation values to these shared memory blocks.
    2213
    23         //The modulation is specified as a vector with 192 4-bit elements
    24         //The indicies below represent the subcarrier index:
    25         // x[0:63] specify the full-rate modulation for antenna A
    26         // x[64:127] specify the full-rate modulation for antenna B
    27         // x[128:191] specify the base-rate modulation
    28 
    29         //When re-cast as a vector of unsigned ints, the subcarrier indicies are mapped like:
    30         // [ [7 6 5 4 3 2 1 0] [15 14 13 12 11 10 9 8] [23 22 21 20 19 18 17 16] ...]
    31         //Thus,
    32         //  unsigned int modMasks_qpsk[24] = {0x02222220, 0x22222222, 0x22022222 ...
    33         //results in zeros at subcarriers 0, 7 and 21...
    34 
    35         //QPSK modulation on 48 subcarriers
    36         unsigned int modMasks_qpsk[24] = {0x02222220, 0x22222222, 0x22022222, 0x00000222, 0x22000000, 0x22220222, 0x22222222, 0x22222202, 0x02222220, 0x22222222, 0x22022222, 0x00000222, 0x22000000, 0x22220222, 0x22222222, 0x22222202, 0x02222220, 0x22222222, 0x22022222, 0x00000222, 0x22000000, 0x22220222, 0x22222222, 0x22222202};
    37 
    38         //16-QAM on 48 subcarriers
    39         unsigned int modMasks_16qam[24] = {0x04444440, 0x44444444, 0x44044444, 0x00000444, 0x44000000, 0x44440444, 0x44444444, 0x44444404, 0x04444440, 0x44444444, 0x44044444, 0x00000444, 0x44000000, 0x44440444, 0x44444444, 0x44444404, 0x04444440, 0x44444444, 0x44044444, 0x00000444, 0x44000000, 0x44440444, 0x44444444, 0x44444404};
    40 
    41         //64-QAM on 48 subcarriers
    42         unsigned int modMasks_64qam[24] = {0x06666660, 0x66666666, 0x66066666, 0x00000666, 0x66000000, 0x66660666, 0x66666666, 0x66666606, 0x06666660, 0x66666666, 0x66066666, 0x00000666, 0x66000000, 0x66660666, 0x66666666, 0x66666606, 0x06666660, 0x66666666, 0x66066666, 0x00000666, 0x66000000, 0x66660666, 0x66666666, 0x66666606};
    43 
    44         unsigned char i;
    45 
    46         for(i=0; i<24; i++)
    47         {
    48                 //Uncomment one of the following lines to select the modulation scheme at the Transmitter
    49                 *((volatile unsigned int*)(XPAR_OFDM_TXRX_MIMO_OPBW_0_BASEADDR+ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET+i*sizeof(int))) = modMasks_qpsk[i];
    50                 //*((volatile unsigned int*)(XPAR_OFDM_TXRX_MIMO_OPBW_0_BASEADDR+ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET+i*sizeof(int))) = modMasks_16qam[i];
    51                 //*((volatile unsigned int*)(XPAR_OFDM_TXRX_MIMO_OPBW_0_BASEADDR+ofdm_TxRx_mimo_SMWO_TxModulation_OFFSET+i*sizeof(int))) = modMasks_64qam[i];
    52         }
    53 
    54         for(i=0; i<24; i++)
    55         {
    56                 //Uncomment one of the following lines to select the modulation scheme at the Receiver
    57                 *((volatile unsigned int*)(XPAR_OFDM_TXRX_MIMO_OPBW_0_BASEADDR+ofdm_TxRx_mimo_SMWO_RxModulation_OFFSET+i*sizeof(int))) = modMasks_qpsk[i];
    58                 //*((volatile unsigned int*)(XPAR_OFDM_TXRX_MIMO_OPBW_0_BASEADDR+ofdm_TxRx_mimo_SMWO_RxModulation_OFFSET+i*sizeof(int))) = modMasks_16qam[i];
    59                 //*((volatile unsigned int*)(XPAR_OFDM_TXRX_MIMO_OPBW_0_BASEADDR+ofdm_TxRx_mimo_SMWO_RxModulation_OFFSET+i*sizeof(int))) = modMasks_64qam[i];
    60         }
    61 }
    62 }}}
    6314
    6415= BER Testing =