Performance Management The material covered in this chapter can reduce DSP hardware costs by a factor of 2 : 1 or more. Thus it is pivotal and in some sense the culmination of the SDR design aspects of this text. I. OVERVIEW OF PERFORMANCE MANAGEMENT Resources critical to software radio architecture include I/O bandwidth, memory, and processing capacity. | Software Radio Architecture Object-Oriented Approaches to Wireless Systems Engineering Joseph Mitola III Copyright 2000 John Wiley Sons Inc. ISBNs 0-471-38492-5 Hardback 0-471-21664-X Electronic 13 Performance Management The material covered in this chapter can reduce DSP hardware costs by a factor of 2 1 or more. Thus it is pivotal and in some sense the culmination of the SDR design aspects of this text. I. OVERVIEW OF PERFORMANCE MANAGEMENT Resources critical to software radio architecture include I O bandwidth memory and processing capacity. Good estimates of the demand for such resources result in a well-informed mapping of software objects to heterogeneous multiprocessing hardware. Depending on the details of the hardware the critical resource may be the capacity of the embedded processor s memory bus mass storage or some other input output I O subsystem. A. Conformable Measures of Demand and Capacity MIPS MOPS and MFLOPS are not interchangeable. Many contemporary processors for example include pipelined floating point arithmetic or single instruction FFT butterfly operations. These operations require processor clock cycles. One may however express demand in the common measure of millions of operations per second MOPS where an operation is the average work accomplished in a single clock cycle of an SDR word width and operation mix. Although software radios may be implemented with 16-bit words this requires systematic control of dynamic range in each processing stage . through automatic gain control and other normalization functions . Thus 32-bit equivalent words provide a more useful reference point in spite of the fact that FPGA implementations use limited precision arithmetic for efficiency. The mix of computation . filtering versus I O . for a T1 multiplexer depends strongly on the radio application so this chapter provides tools for quantitatively determining the instruction mix for a given SDR application. One useful generalization for the mix is
