Construction of Irregular LDPC (Low Density Parity Check) codes using RS (Reed-Solomon) codes or GRS (Generalized Reed-Solomon) codes. As described herein, a wide variety of irregular LDPC codes may be generated using GRS or RS codes. The corresponding LDPC matrix of such an irregular LDPC code may be constructed by performing partial-matrix processing (including decomposition and partial-matrix replacement thereof) of a parity check matrix that corresponds to a GRS-based regular LDPC code. Such an irregular LDPC code may be appropriately designed using these principles thereby generating a code that is suitable for use in wireless communication systems including those that comply with the recommendation practices and standards being developed by the IEEE (Institute of Electrical & Electronics Engineers) 802.11n Task Group (i.e., the Task Group that is working to develop a standard for 802.11 TGn (High Throughput)).