11.3 Highlights of HomeRF 2.0

To improve the transmission performance of HomeRF, especially for the increased throughput of asynchronous data, the HomeRF 2.0 standards have been proposed and approved. HomeRF 2.0 enables up to eight voice connections and is capable of providing streaming audio and video sessions. The high transmission throughput of HomeRF is made possible by using a GFSK signaling rate of 5 MHz instead of 1 MHz. The higher signaling rate results in transmission throughputs of 5 and 10 Mbps for 2FSK and 4FSK modulations, respectively. Within the ISM band of between 2430 and 2477 MHz with a single channel bandwidth of 5 MHz, 15 instead of 75 non-overlapping channels can be allocated. Using equalization techniques, similar receiver sensitivities can be maintained for 2FSK and 4FSK modulations under normal channel spread conditions. The maximum transmit power for HomeRF 2.0 is increased to 27 dBm.

At a bandwidth of 5 MHz, the receiver front-end noise level P_noise is calculated according to the input resistor thermal noise level of P_R = kT = 174 dBm/Hz, the antenna and amplifier noise figure of NF = 14 dB, and the signal bandwidth of B = 5 x 10⁶ = 67. We have

Equation 11.9

Assuming the required signal level of 76 and 62 dBm for 2FSK and 4FSK, respectively, the SNRs at the receiver front end are about 31 and 17 dB. The corresponding channel capacities for the HomeRF 2.0 environment are

Equation 11.10

Equation 11.11