Optimization of Unicast Services Transmission for Broadcast Channels in Practical Situations
Bell Labs Technical Journal
Superposition Coding with Unequal Error Protection for the Uplink of Overloaded DS-CDMA System
Wireless Personal Communications: An International Journal
Hi-index | 754.84 |
This paper shows that several transmitters operating in an additive white Gaussian noise environment can send at rates strictly dominating time-multiplex and frequency-multiplex rates by use of a superposition scheme that pools the time, bandwidth, and power allocations of the transmitters. This pooling can be achieved without cooperative action, except for agreement on the actual rate of transmission each transmitter will allow itself. The superposition scheme involves subtraction from the received signal of the estimated signals sent by the other transmitters, followed by decoding of the intended signal. This scheme has been shown to be optimal. We conclude that present methods of allocating different frequency bands to different transmitters are necessarily suboptimal.