Over the last few years, power line communication (PLC) has gained importance for high-speed data communication. One of the major concerns in PLC is noise and high data rate, thus, several schemes have been adopted to minimize noise over PLCs and improve data rate. One of the promising approaches is the use of multi band (MB)–orthogonal frequency division multiplexing (OFDM) ultra wideband (UWB) to achieve date rates over 200 Mbps. One of the approaches is to integrate MB-OFDM UWB with digital down converter (DDC) for power line communication. A modified discrete wavelet transform (DWT) architecture with reduced memory, two-stage DDC, and modified DDS blocks are designed to generate MB-OFDM signal for PLC. From the results obtained, it is found that DWT-based MB-OFDM UWB outperformed FFT-based MB-OFDM UWB by approximately 6-dB gain in bit error rate (BER). Haar wavelet showed best performance over Biorthogonal (bior3.3, bior5.5), Daubechies (db2, db4), and reverse Biorthogonal (rbior3.3, rbior5.5) by approximately 2 dB. Though QPSK yielded better BER through observations, it is used for a constant power output transmitter, while QAM works better for a linear transmitter.