diff --git a/src/downconvert_and_correlate.jl b/src/downconvert_and_correlate.jl
index d6b1bec..b19727b 100644
--- a/src/downconvert_and_correlate.jl
+++ b/src/downconvert_and_correlate.jl
@@ -37,8 +37,6 @@ function downconvert_and_correlate_kernel(
     res_im,
     signal_re,
     signal_im,
-    carrier_re,
-    carrier_im,
     codes,
     code_frequency,
     correlator_sample_shifts,
@@ -59,16 +57,16 @@ function downconvert_and_correlate_kernel(
     iq_offset = blockDim().x
     cache_index = threadIdx().x - 1 
 
-    code_phase = accum_re = accum_im = dw_re = dw_im = 0.0f0
+    code_phase = accum_re = accum_im = dw_re = dw_im = carrier_re = carrier_im = 0.0f0
     mod_floor_code_phase = Int(0)
 
     if sample_idx <= num_samples && antenna_idx <= num_ants && corr_idx <= num_corrs
         # generate carrier
-        carrier_im[sample_idx], carrier_re[sample_idx] = CUDA.sincos(2π * ((sample_idx - 1) * carrier_frequency / sampling_frequency + carrier_phase))
+        carrier_im, carrier_re = CUDA.sincos(2π * ((sample_idx - 1) * carrier_frequency / sampling_frequency + carrier_phase))
     
         # downconvert with the conjugate of the carrier
-        dw_re = signal_re[sample_idx, antenna_idx] * carrier_re[sample_idx] + signal_im[sample_idx, antenna_idx] * carrier_im[sample_idx]
-        dw_im = signal_im[sample_idx, antenna_idx] * carrier_re[sample_idx] - signal_re[sample_idx, antenna_idx] * carrier_im[sample_idx]
+        dw_re = signal_re[sample_idx, antenna_idx] * carrier_re + signal_im[sample_idx, antenna_idx] * carrier_im
+        dw_im = signal_im[sample_idx, antenna_idx] * carrier_re - signal_re[sample_idx, antenna_idx] * carrier_im
 
         # calculate the code phase
         code_phase = code_frequency / sampling_frequency * ((sample_idx - 1) + correlator_sample_shifts[corr_idx]) + start_code_phase
@@ -109,11 +107,8 @@ function downconvert_and_correlate_kernel_wrapper(
     system,
     signal,
     correlator,
-    code_replica,
     code_phase,
-    carrier_replica,
     carrier_phase,
-    downconverted_signal,
     code_frequency,
     correlator_sample_shifts,
     carrier_frequency,
@@ -138,9 +133,7 @@ function downconvert_and_correlate_kernel_wrapper(
         res_re, 
         res_im, 
         signal.re, 
-        signal.im, 
-        carrier_replica.re, 
-        carrier_replica.im, 
+        signal.im,
         system.codes,
         Float32(code_frequency),
         correlator_sample_shifts,
diff --git a/src/tracking_loop.jl b/src/tracking_loop.jl
index 7e426be..585a6b5 100644
--- a/src/tracking_loop.jl
+++ b/src/tracking_loop.jl
@@ -303,11 +303,8 @@ function downconvert_and_correlate!(
         system,
         view(signal, signal_start_sample:signal_start_sample - 1 + num_samples_left,:),
         correlator,
-        code_replica,
         code_phase,
-        carrier_replica,
         carrier_phase,
-        downconverted_signal,
         code_frequency,
         correlator_sample_shifts,
         carrier_frequency,
@@ -341,11 +338,8 @@ function downconvert_and_correlate!(
         system,
         view(signal, signal_start_sample:signal_start_sample - 1 + num_samples_left),
         correlator,
-        code_replica,
         code_phase,
-        carrier_replica,
         carrier_phase,
-        downconverted_signal,
         code_frequency,
         correlator_sample_shifts,
         carrier_frequency,
@@ -364,7 +358,7 @@ end
 function choose(replica::CarrierReplicaCPU, signal::AbstractArray{Complex{T}}) where T <: Number
     replica.carrier_f32
 end
-function choose(replica::StructVector{ComplexF32, NamedTuple{(:re, :im), Tuple{CuArray{Float32, 1, CUDA.Mem.DeviceBuffer}, CuArray{Float32, 1, CUDA.Mem.DeviceBuffer}}}, Int64}, signal::AbstractArray)
+function choose(replica::Nothing, signal::AbstractArray)
     nothing
 end
 function choose(replica::DownconvertedSignalCPU, signal::AbstractArray{Complex{Float64}})
diff --git a/src/tracking_state.jl b/src/tracking_state.jl
index 1413c63..f4d82ea 100644
--- a/src/tracking_state.jl
+++ b/src/tracking_state.jl
@@ -64,7 +64,7 @@ struct TrackingState{
         COLF <: AbstractLoopFilter,
         CN <: AbstractCN0Estimator,
         DS <: Union{DownconvertedSignalCPU, Nothing},
-        CAR <: Union{CarrierReplicaCPU, StructVector{ComplexF32, NamedTuple{(:re, :im), Tuple{CuArray{Float32, 1, CUDA.Mem.DeviceBuffer}, CuArray{Float32, 1, CUDA.Mem.DeviceBuffer}}}, Int64}},
+        CAR <: Union{CarrierReplicaCPU, Nothing},
         COR <: Union{Vector{Int8}, Nothing}
     }
     prn::Int
@@ -191,10 +191,10 @@ function TrackingState(
         code_phase = mod(code_phase, get_code_length(system))
     end
     downconverted_signal = nothing
-    carrier = gen_blank_carrier_gpu(system, num_samples)
+    carrier = nothing
     code = nothing
 
-    TrackingState{S, C, CALF, COLF, CN, Nothing, typeof(carrier), Nothing}(
+    TrackingState{S, C, CALF, COLF, CN, Nothing, Nothing, Nothing}(
         prn,
         system,
         carrier_doppler,