Decentralized Limited-Feedback Multiuser MIMO for Temporally Correlated Channels

Table 1

Pseudocode for the proposed algorithm (“DAO-D-JAC”). This process occurs at the end of each slot 𝑙>0. “U. 𝑖” denotes processing at the 𝑖th receiver, “Tx.” denotes processing at the transmitter.

U. 𝑖:	Set 𝐇=𝐇𝑖(𝑙𝐿−1), the most recent channel sample
U. 𝑖:	Set 𝐐 to the most recent estimate of 𝐐𝑖
U. 𝑖:	Set 𝐐 to the updated filtered covariance matrix 𝐐𝑖 from (6)
U. 𝑖:	compute 𝐑=𝐇^†𝐐^−1𝐇
U. 𝑖:	For each rotor in the update: compute the angle pair (𝛼,𝛽) based on 𝐑 and the receive-side auxiliary matrix Φ𝑖, as in [6]. Update Φ𝑖 and the own weights 𝐰𝑖. Quantize (𝛼,𝛽) and include it in the feedback message 𝐛𝑖(𝑙)
Tx.:	For each rotor in the update of user 𝑖: retrieve (𝛼,𝛽) from 𝐛𝑖(𝑙), assemble the corresponding Givens rotor 𝐉^𝑖1,𝑞. Update the transmit-side Φ𝑖,𝐰𝑖 with (5).