3.3Vectorized formulation of the input-output relation
信道的脉冲响应可以写为 h(τ,ν)=i=1∑Phiδ(τ−τi)δ(ν−νi)即假设两根天线之间存在P条路径 ??? Define τi=MΔfαiand νi=NTβi ,where αi and βi are integers denoting the indices of the delay tap (with delay τi) and Doppler tap (with Doppler value νi). In practice, although the delay and Doppler values are not exactly integer multiples of the taps, they can be well approximated by a few delay-Doppler taps in the discrete domain. 有了上面的假设之后,可以得到y[k,l]=i=1∑Phi′x[((k−βi))N,((l−αi))M]+v[k,l]用向量形式可以表示为y=Hx+v ??? xk+Nl=x[k,l],周期性?