I. Field
The present invention relates generally to communication, and more specifically to techniques for transmitting overhead information for reception of multiple data streams in a communication system.
II. Background
A base station in a wireless communication system may simultaneously transmit multiple data streams for broadcast, multicast, and/or unicast services. A broadcast transmission is sent to all wireless devices within a designated coverage area, a multicast transmission is sent to a group of wireless devices, and a unicast transmission is sent to a specific wireless device. For example, the base station may broadcast a number of data streams for multimedia (e.g., television) programs via a terrestrial radio link for reception by wireless devices. In general, the base station may transmit any number of data streams, which may change over time, and each data stream may have a fixed or variable data rate.
A wireless device within the coverage area of the base station may be interested in receiving only one or few specific data streams among the multiple data streams transmitted by the base station. If the base station multiplexes all data streams onto one composite stream prior to transmission, then the wireless device may need to receive the signal transmitted by the base station, process (e.g., downconvert, demodulate, and decode) the received signal to obtain the composite stream sent by the base station, and perform demultiplexing to extract the one or few specific data streams of interest. This type of processing may not be problematic for receiver units intended to be powered on all the time. However, many wireless devices are portable and powered by internal batteries. Continual demodulation and decoding of the received signal to recover just one or few data streams of interest may consume significant amounts of battery power, which may greatly shorten the “ON” time for the wireless device.
If the multiple data streams are transmitted separately, then the base station may also transmit control information on a dedicated control channel to indicate when and where each data stream will be transmitted. In this case, the wireless device may need to continuously decode the dedicated control channel to obtain control information for each data stream of interest, which can deplete battery power. The wireless device may also need to simultaneously decode each data stream of interest along with the dedicated control channel, which can increase the complexity of the wireless device.
There is therefore a need in the art for techniques to send overhead information such that individual data streams of interest to wireless devices may be efficiently received with reduced power consumption.