公开(公告)号：DE60217910D1

公开(公告)日：2007-03-15

申请号：DE60217910

申请日：2002-12-17

Applicant: QUALCOMM INC

Inventor： LUNDBY A

IPC: H04L12/18 ,  H04L1/00 ,  H04L1/16 ,  H04L12/56 ,  H04W4/06 ,  H04W4/08 ,  H04W8/26 ,  H04W12/00 ,  H04W28/04 ,  H04W72/08

Abstract: Methods and apparatus are presented for efficient broadcasting in wireless packet data systems. A single MAC_ID is used for broadcasting to a group of subscribers. By using the channel quality information of the group of subscribers, a base station determines the identity of the subscriber with the worst channel conditions. The timing and the transmission format of the multi-cast are then tailored so that the subscriber with the worst channel conditions is capable of recovering the transmission. If the timing and the transmission format is chosen in relation to subscriber with the worst channel conditions, it is probable that other subscribers will be able to recover the transmission as well. Hence, only a single MAC_ID need to be used to make a single broadcast, rather than sending multiple transmissions to multiple subscribers.

公开(公告)号：DE60214834D1

公开(公告)日：2006-11-02

申请号：DE60214834

申请日：2002-03-29

Applicant: QUALCOMM INC

Inventor： LUNDBY A

IPC: H04B7/005 ,  H04B1/707 ,  H04B7/26 ,  H04L27/34 ,  H04L27/36 ,  H04L27/38

Abstract: In a communication system, a method and an accompanying apparatus provide for efficient modulation and demodulation processes. In a transmitter (100), a ratio of power level of a communication channel over power level of a pilot channel is determined to produce a power level ratio. The power level ratio is quantized within a finite digital word. A quantized quadrature amplitude modulation distance, in a quadrature amplitude modulation constellation, is determined based on the quantized power level ratio. A signal, in accordance with a quadrature amplitude modulation technique, is modulated using the quantized distance, and transmitted to a receiver (160).