Alcatel Lucent

Bijun Zhang

Yu Chen

Thorsten Wild

Yonggang Wang

Zhongji Hu

He Wang

Bernd Haberland

Pingping Xing

The present invention proposes a method, device and base station for cooperative beam forming based on MBMS fixed grid of beams GoB. The cooperative beam forming method comprises following steps: grouping users into cell central user group and cell edge user group (S); performing cell central user group multiplexing based on superposition coding (S); performing cooperative beam forming operation based on fixed grid of beams GoB for cell edge user group (S).

Cooperative beam forming method, apparatus and base station

Disclosed is a method for triggering retransmission in a multicast system, including a base station eNB setting a retransmission condition based on a channel state indication and transmitting the set retransmission condition to a user equipment UE; and the UE comparing the current channel state indication of the UE with the received retransmission condition when receiving an error block, and feeding back a NACK signaling to the eNB trigger a retransmission when the retransmission condition is satisfied. The method according to the present invention is to restrict the trigger of the NACK signaling, by setting the condition of the UE feeding back the NACK signaling when the UE received the error block. Then the feedback signaling on the uplink channel would be restricted, and the retransmission probability would be limited in an appropriate region as in Rel 6 HSDPA, therefore the optimal ratio of efficiency over power would be achieved. Consequently, the number of NACK signaling is restricted so as to avoid the uplink overload. Meanwhile, the retransmission probability is limited so that the optimal ratio of efficiency over power may be achieved.

Method for triggering retransmission in a multicast system and apparatus implementing the method

Disclosed is a method for mapping pilot signals in a multiplexing mode of unicast service and Multimedia Broadcast/Multicast Service (MBMS). The method comprises the steps of: generating pilot symbols for the unicast service and the MBMS service, respectively; mapping the pilot symbols for the MBMS service to multiple transmit antennas such that, in a subframe, the pilot symbols for the MBMS service for each antenna are arranged in a same time domain and adjacent to each other, the pilot symbols for the MBMS service for the same transmit antenna are spaced from each other by a predetermined number of subcarriers in the frequency domain and by a predetermined number of OFDM symbols in the time domain, and the pilot symbols for the MBMS service for the same transmit antenna are arranged in a staggered form along the time domain, and mapping the pilot symbols for the unicast service at the same time.

Method and apparatus for mapping pilot signals in multiplexing mode of unicast and broadcast/multicast services

Growing community of inventors

Shanghai, China

Bijun Zhang