- Uses Half-Rate Convolutional Encoder
- Outputs Two Bits of Encoded Data for Every Input Bit
The forward link uses a half-rate convolutional encoder to provide error correction capabilities. This type of encoder accepts incoming serial data and outputs encoded data derived from a series of delay taps and summing nodes.
A half-rate encoder produces two output symbols for every symbol input. For the CDMA forward link, the half-rate encoder produces two 9,600 bps serial data streams when driven by a single 9,600 bps data stream.
These two 9,600 serial data streams are combined at a higher rate to produce a single 19,200 bps data stream. The resulting redundancy in the digital data after convolutional encoding imparts powerful error correction capability to the TIA CDMA cellular system.