DSP Blockset

Technical Conventions

The following sections provides a brief overview of the technical conventions used in this guide, and provides pointers to more detailed information:

• Signal Dimension Nomenclature
• Frame-Based Signal Nomenclature
• Sampling Nomenclature

Signal Dimension Nomenclature

The DSP Blockset fully supports the Simulink matrix format, which is described in "Working with Signals" in the Simulink documentation. The nomenclature used for vectors and matrices in the DSP Blockset is described below.

Matrices.   Any mention of a matrix in the DSP Blockset is a reference to a Simulink matrix. A Simulink matrix is the same as a MATLAB matrix, a two-dimensional (2-D) array of values, organized as rows and columns. As in MATLAB, a matrix can be indexed by one or two values. The size of a matrix is described by the number of rows M and the number of columns N. In the DSP Blockset, matrix size is usually denoted by the compact expression M-by-N or MxN, and occasionally by the MATLAB notation [M N].

For instance, a 2-by-3 matrix, like matrix u below, has two rows and three columns:

This matrix can be represented in MATLAB notation as

• u = [1 2 3;4 5 6]        % A 2-by-3 matrix
  

In the online help, matrix elements are indexed using either subscript notation or MATLAB notation. For example, u23 and u(2,3) both refer to the element in the third column of the second row. The number of channels in a frame-based matrix is the number of columns, N. More information about matrices can be found in Multichannel Signals.

Vectors.   The DSP Blockset refers to three different kinds of vectors:

• Row vector -- A 1-by-N matrix

• Column vector -- An M-by-1 matrix

• One-dimensional (1-D) vector -- A 1-D vector is also known as a Simulink vector or unoriented vector. A 1-D vector is a one-dimensional array of values, an ordered list that has no row or column orientation. There is no MATLAB equivalent for 1-D vectors since all MATLAB vectors have either a row or column orientation. Most blocks in the DSP Blockset treat 1-D vectors as column vectors.

The size or length of a vector is the number of elements that it contains (M for a column vector or N for a row vector).

Arrays.   The number of pages, P, of a three-dimensional array in the MATLAB workspace refers to the size of its third dimension:

• A(:,:,1) = [1 2 3;4 5 6]     % The first page of a 3-page array
  A(:,:,2) = [7 8 9;0 1 2]     % The second page
  A(:,:,3) = [3 4 5;6 7 8]     % The last page
  

Array size is frequently denoted by the compact expression M-by-N-by-P or MxNxP.

Frame-Based Signal Nomenclature

A frame of data is a collection of sequential samples from a single channel. In Simulink, a length-M frame of data is represented by an M-by-1 matrix (column vector). A multichannel signal with N channels and M samples per frame is represented as an M-by-N matrix. See Multichannel Signals for more about multichannel signals.

Signals in Simulink can be either frame-based or sample-based. You can typically specify the frame status (frame-based or sample-based) of any signal that you generate using a source block (from the DSP Sources library). Most other DSP blocks generally preserve the frame status of an input signal, but some do not. See Creating Signals for more information.

Sampling Nomenclature

Important sampling-related notational conventions are listed in Sample Rates and Frame Rates.

How to Run Examples in the MATLAB Help Browser

Typographical Conventions