The sampling jitter is particularly problematic in systems where high-frequency signals are sampled. This paper addresses the sampling jitter estimation and cancellation task in the direct RF sub-sampling type radio receivers. The proposed jitter estimation method is based on carefully injecting or superimposing an additional reference signal to the received signal at sampler input. Proper digital signal processing methods are then devised and applied to estimate the sampling jitter realizations from the obtained jittered samples. Using these jitter estimates, combined with proper jitter modelling, the jitter effects can then be efficiently removed from the actual received signal. Careful performance analysis of the overall estimation-cancellation scheme is also carried out using computer simulations with 3GPP LTE type multicarrier signals, assuming also different amounts of RF filtering prior to RF sub-sampling stage.