A transmitter for wireless communication comprising: an input for receiving baseband data in a first signal having a first frequency; first circuitry for increasing the first frequency, to form a second signal having a second frequency, in response to a first frequency reference signal; second circuitry for increasing the second frequency, to form a third signal having a third frequency, in response to a second frequency reference signal; a filter for filtering the second signal, an antenna for transmitting the baseband data at a final transmission channel frequency selected as a channel from among a band comprising a predetermined set of frequency channels; the first and second circuitry are respectively arranged such that the first frequency reference signal and the second frequency reference signal are variable and are selected in response to the final transmission channel frequency, wherein a spurious signal is the sum and difference of the first frequency reference signal and the second frequency reference signal and their harmonics falling within the transmit or receive band; and a worst case spurious signal is the spurious signal with the smallest order, where the order of the spurious signal is the sum of the absolute value of each of the harmonics of the first and second frequency reference signals (IF2, L02), wherein the first frequency reference signal and the second frequency reference signal are selected such as to increase the order of the worst case spurious signal to achieve a higher order than the third harmonic of the first frequency reference signal, thereby reducing the complexity of the filter. an input for receiving baseband data in a first signal having a first frequency; first circuitry for increasing the first frequency, to form a second signal having a second frequency, in response to a first frequency reference signal; second circuitry for increasing the second frequency, to form a third signal having a third frequency, in response to a second frequency reference signal; a filter for filtering the second signal, an antenna for transmitting the baseband data at a final transmission channel frequency selected as a channel from among a band comprising a predetermined set of frequency channels; the first and second circuitry are respectively arranged such that the first frequency reference signal and the second frequency reference signal are variable and are selected in response to the final transmission channel frequency, wherein a spurious signal is the sum and difference of the first frequency reference signal and the second frequency reference signal and their harmonics falling within the transmit or receive band; and a worst case spurious signal is the spurious signal with the smallest order, where the order of the spurious signal is the sum of the absolute value of each of the harmonics of the first and second frequency reference signals (IF2, L02), wherein the first frequency reference signal and the second frequency reference signal are selected such as to increase the order of the worst case spurious signal to achieve a higher order than the third harmonic of the first frequency reference signal, thereby reducing the complexity of the filter.