A novel portable and wireless biomedical monitoring system featuring on demand wireless data transmission of ECG signals and time-frequency HRV analysis for personal and home healthcare applications is presented in this work. In order to provide comfort and convenience to patients, the device's size, power consumption and portability are of first priority. The ECG processor based on previous hardware design  acquires three-channel ECG biomedical raw data through an analog front-end (AFE) circuit, and it measures the time between successive heart beats on lead II as RR intervals for HRV analysis. Functions such as QRS complex peak detection, RR intervals calculation, and time-frequency analysis of HRV have also been developed in hardware. A real-time HRV analysis processor is realized by employing a Lomb periodogram for time-frequency power spectral density (PSD) analysis of the heart rate. The proposed ECG monitoring system has been implemented in Field-Programmable Gate Arrays (FPGA) and it features high integration density, portability, wireless transmission and low cost.