QPSK verilog调制解调代码

以下是一个简单的QPSK调制解调的Verilog代码，其中包括了载波生成、调制、解调、差分解码等模块：

module qpsk_mod_demod(
  input clk, rst, en, 
  input [7:0] data_in,
  output reg [7:0] data_out
);

  parameter pi = 3.14159265359;
  parameter f_c = 1000000; // 载波频率
  parameter f_s = 8000; // 采样频率
  parameter T_s = 1/f_s; // 采样时间间隔
  parameter N = 8; // 每个符号对应的比特数

  reg [7:0] data_ifs;
  reg [N-1:0] data_ifs_idx;
  reg [1:0] phase;
  reg [7:0] q_data, i_data, q_data_out, i_data_out;
  reg [N-1:0] count;
  reg [7:0] data_out_tmp;
  reg [1:0] phase_out;

  // 载波生成模块
  reg [23:0] phase_acc;
  reg signed [15:0] sine, cosine;
  always @(posedge clk) begin
    if (rst) begin
      phase_acc <= 0;
    end else begin
      phase_acc <= phase_acc + $signed({f_c*T_s, 8'b0});
    end
  end
  assign sine = $signed($sin(phase_acc[23:8] * 2 * pi / (2 ** 16)));
  assign cosine = $signed($cos(phase_acc[23:8] * 2 * pi / (2 ** 16)));

  // 调制模块
  always @(posedge clk) begin
    if (rst) begin
      phase <= 0;
      data_ifs_idx <= 0;
    end else if (en) begin
      // 根据相位情况将比特数据分为 I、Q 两路
      if (phase == 2'b00) begin
        i_data <= data_in[N*data_ifs_idx +: N];
        q_data <= 8'b0;
      end else if (phase == 2'b01) begin
        i_data <= 8'b0;
        q_data <= data_in[N*data_ifs_idx +: N];
      end else if (phase == 2'b10) begin
        i_data <= -data_in[N*data_ifs_idx +: N];
        q_data <= 8'b0;
      end else begin // phase == 2'b11
        i_data <= 8'b0;
        q_data <= -data_in[N*data_ifs_idx +: N];
      end
      data_ifs_idx <= data_ifs_idx + 1;
      if (data_ifs_idx == 255) begin
        data_ifs_idx <= 0;
      end
      // 将 I、Q 两路数据相乘并累加
      data_ifs <= i_data * cosine + q_data * sine;
      phase <= phase + 1;
      if (phase == 2'b11) begin
        phase <= 0;
      end
    end
  end

  // 解调模块
  always @(posedge clk) begin
    if (rst) begin
      count <= 0;
      i_data_out <= 0;
      q_data_out <= 0;
    end else if (en) begin
      if (count == N-1) begin
        // 将 I、Q 两路数据相乘并累加
        i_data_out <= i_data_out + data_ifs * cosine;
        q_data_out <= q_data_out + data_ifs * sine;
        count <= 0;
        phase_out <= phase_out + 1;
        if (phase_out == 2'b11) begin
          phase_out <= 0;
        end
        // 根据 I、Q 两路数据确定比特数据
        if (i_data_out > 0 && q_data_out > 0) begin
          data_out_tmp <= {2'b00, i_data_out[N-1:2]};
        end else if (i_data_out < 0 && q_data_out > 0) begin
          data_out_tmp <= {2'b01, -i_data_out[N-1:2]};
        end else if (i_data_out < 0 && q_data_out < 0) begin
          data_out_tmp <= {2'b10, i_data_out[N-1:2]};
        end else begin // i_data_out > 0 && q_data_out < 0
          data_out_tmp <= {2'b11, q_data_out[N-1:2]};
        end
        data_out <= data_out_tmp;
      end else begin
        count <= count + 1;
      end
    end
  end

endmodule

// 差分解码模块
module qpsk_diff_decoder(
  input clk, rst, 
  input [7:0] data_in,
  output reg [7:0] data_out
);

  reg [7:0] data_reg;
  reg [7:0] data_out_tmp;

  always @(posedge clk) begin
    if (rst) begin
      data_reg <= 8'b0;
    end else begin
      data_out_tmp <= data_in ^ data_reg;
      data_out <= data_out_tmp[N-1:0];
      data_reg <= data_out_tmp;
    end
  end

endmodule

这个代码实现了一个基于差分码的QPSK调制解调器，其中的qpsk_mod_demod模块将输入的比特流进行QPSK调制，输出调制后的IQ信号，再将IQ信号进行解调，输出解调后的比特流。qpsk_diff_decoder模块对输出的比特流进行差分解码，得到最终的解调结果。