BLAST(Bell Labs Layered Space-Time)即貝爾實驗室分層空時,是貝爾實驗室提出的一種能夠達到極高數據傳輸速率的無線通信技術。這種技術在一個帶限無線信道內,通過多天線技術充分利用空間復用,使得信道容量隨着天線數的增加呈線性增長,有着極高的頻譜效率。
完整的檢測算法可以概括為遞歸如下:
初始化:
i ← 1 r 1 = r G 1 = ( H H H + σ 2 I N t ) − 1 H H k 1 = arg min ‖ ( G 1 ) j ‖ 2 {\displaystyle {\begin{aligned}i&\leftarrow 1\\r_{1}&=r\\G_{1}&=(H^{H}H+\sigma ^{2}I_{N_{t}})^{-1}H^{H}\\k_{1}&=\arg \min \left\|(G_{1})_{j}\right\|^{2}\\\end{aligned}}}
遞歸:
w k = ( G i ) k i y k = w k T × r i s ^ k = s i g n ( y k ) r i + 1 = r i − s ^ k ( H ) k i G i + 1 = ( ( H i H H i ) + σ 2 I N t ) − 1 H i H k i + 1 = arg min ‖ ( G i + 1 ) j ‖ 2 i ← i + 1 {\displaystyle {\begin{aligned}w_{k}&=(G_{i})_{ki}\\y_{k}&=w_{k}^{T}\times r_{i}\\{\hat {s}}_{k}&=sign(y_{k})\\r_{i+1}&=r_{i}-{\hat {s}}_{k}(H)_{ki}\\G_{i+1}&=((H_{i}^{H}H_{i})+\sigma ^{2}I_{Nt})^{-1}H_{i}^{H}\\k_{i+1}&=\arg \min \left\|(G_{i+1})_{j}\right\|^{2}\\i&\leftarrow i+1\end{aligned}}}