Abstract:

A low complexity bit and power allocation algorithm is proposed to minimize the total transmit power under transmission rate and bit error ratio constraints in multiple-input multiple-output systems with inaccurate channel state information. With monotony, the non-convex optimization problem is simplified to a convex one. Then the optimal solution is derived in the nonnegative real field. And the final bit and power allocation is obtained after adjusting the real solution into discrete bit numbers. The simulations show that the proposed algorithm has the same power efficiency with the optimal robust greedy algorithm while its computation complexity is much lower.

Key words: multiple-input multiple-output, adaptive modulation, bit and power allocation, channel state information