-- ------------------------------------------------------------- -- Additional material to the book-- Modeling and Simulation for RF System Design-- ---- THIS MODEL IS LICENSED TO YOU "AS IT IS" AND WITH NO WARRANTIES, -- EXPRESSED OR IMPLIED. THE AUTHORS SPECIFICALLY DISCLAIM ALL IMPLIED -- WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.-- THEY MUST NOT HAVE ANY RESPONSIBILITY FOR ANY DAMAGES, FINANCIAL OR-- LEGAL CLAIMS WHATEVER.-- ------------------------------------------------------------- Name:     AWGN test bench-- -- Description:-- The test-bench shows the effects of additive white Gaussian-- noise on a transmitted signal. In time domain a noisy signal-- can be observed. In frequency domain this noise is white-- up to FS_NOISE at least while in a histogram the Gaussian-- nature of the distribution is to be seen.---- Literature:-- ---- Dependencies: -- ------------------------------------------------------------- Logical Library         Design unit-- ------------------------------------------------------------- IEEE_proposed           ELECTRICAL_SYSTEMS-- IEEE                    MATH_REAL-- WORK                    P_SIN(SINGLE_TONE)-- --------------------------------------------------------------- Source:-- section7.3.9_awgn/tb/bench.vhd-- -----------------------------------------------------------library IEEE, IEEE_proposed;                                              use IEEE_proposed.ELECTRICAL_SYSTEMS.all;  use IEEE.MATH_REAL.all;  use WORK.all;entity BENCH is end BENCH;architecture TEST_AWGN of BENCH is  --constants  constant  FIRST_TONE :  REAL:= -30.0;  constant  FIRST_FREQ :  REAL:= 1.0e03;  constant  SIGTONOISE :  REAL:= 20.0;  constant  FS_NOISE   :  REAL:= 1.0e06;  constant  R_s        :  REAL:=  50.0;     --terminals  terminal N_1, N_2, N_VDD: ELECTRICAL;  --branch quantities  quantity V_R2  across I_R2  through N_2;  begin                                                              V_R2 == R_S * I_R2;                          SRC1: entity P_SIN(SINGLE_TONE)    generic map ( PA_DBM => FIRST_TONE,                  FREQ   => FIRST_FREQ)       port map (P=>N_1, M=>ELECTRICAL_REF);  CHN: entity CHANNEL(AWGN)    generic map ( PS_DBM => FIRST_TONE,                  S_TO_N => SIGTONOISE,		  FS_NOISE => FS_NOISE)       port map (P_IN=>N_1, P_OUT=>N_2);                        end architecture TEST_AWGN;