The paper proposes joint power control and beamforming schemes for cellular systems using adaptive arrays at base stations. The uplink scheme minimizes mobile transmitted power while maintaining a minimum signal-to-interference-and-noise ratio (SINR) at each link. A downlink diversity scheme is also introduced, where transmit weight vectors and power allocations are jointly calculated to ensure a target SINR at each mobile. The proposed algorithms minimize total transmitted power and can be implemented in decentralized systems in reciprocal networks without global channel measurements. In nonreciprocal networks, the algorithms require centralized implementation and knowledge of downlink channel responses. The performance of these algorithms is compared with previous methods through numerical studies. The paper includes a detailed system model, receiver diversity combining, joint power control and diversity combining, transmit beamforming, convergence and optimality analysis, practical implementation, and simulation results.The paper proposes joint power control and beamforming schemes for cellular systems using adaptive arrays at base stations. The uplink scheme minimizes mobile transmitted power while maintaining a minimum signal-to-interference-and-noise ratio (SINR) at each link. A downlink diversity scheme is also introduced, where transmit weight vectors and power allocations are jointly calculated to ensure a target SINR at each mobile. The proposed algorithms minimize total transmitted power and can be implemented in decentralized systems in reciprocal networks without global channel measurements. In nonreciprocal networks, the algorithms require centralized implementation and knowledge of downlink channel responses. The performance of these algorithms is compared with previous methods through numerical studies. The paper includes a detailed system model, receiver diversity combining, joint power control and diversity combining, transmit beamforming, convergence and optimality analysis, practical implementation, and simulation results.