This letter considers multiuser detection in variable-spreading-length multi-rate direct-sequence code-division multiple-access systems. A two-layer spreading (TLS) code scheme is proposed which facilitates the low-complexity adaptive implementation of linear minimum mean-square error multiuser receivers in a dual-rate system. It is demonstrated via large system analysis and simulation that imposing a TLS structure does not incur loss in terms of the output signal-to-interference ratio performance.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering
- Adaptive receiver
- Direct-sequence code-division multiple-access (DS-CDMA) systems
- Linear minimum mean-square error (MMSE) receiver
- Multirate systems
- Multiuser detection