Method and apparatus for communicating heterogeneous data traffic simultaneously
using a hybrid Code Division Multiplexing (CDM)/Code Division Multiple Access (CDMA)-Time
Division Multiplexing (TDM)/Time Division Multiple Access (TDMA) system which communicates
data on a per data type basis, rather than a per user or per channel basis. A transmitter
accepts a plurality of data streams, each of which includes either Constant Bit
Rate Data (CBR) or Variable Burst Rate Data (VBR), where CBR is characterized by
a steady data rate and strict latency requirements and VBR is characterized by
a variable data rate with large peaks and lulls and loose latency requirements.
The system identifies each input data stream as CBR or VBR. CBR data is spread
using CDM/CDMA with an appropriate spreading factor for CBR, whereas VBR data is
modulated/encoded and interleaved with CDM/CDMA with an appropriate spreading factor
for VBR and TDM/TDMA, respectively. The modulated CBR data and VBR data streams
are then transmitted by the transmitter to a receiver, which receives and demodulates
the received data streams to recover the original CBR data and VBR data streams.
By communicating input data streams based on whether they include CBR data or VBR
data, the communication system is able to communicate CBR data and VBR data simultaneously
while achieving a superior Quality-of-Service.
