Embodiments of the present disclosure relate to noise floor estimation for signal detection. In example embodiments, a method is provided. The method comprises transforming a received signal into a real-valued plurality of samples based on a predefined signal sequence; determining respective sample thresholds for the samples; detecting for at least one peak sample and/or at least one valley sample in the plurality of samples by comparing the samples with the respective sample thresholds; determining a noise level for based on remaining samples of the samples other than the at least one detected peak sample and/or the at least one detected valley sample; and detecting matching of one of the plurality of samples with the predefined signal sequence based on the noise level. In this way, a more accurate noise estimate is achieved and thus the performance of the signal detection can be achieved.