The use of a blind scheme for suppressing interference in direct-sequence code-division multiple-access (DS /CDMA) communication systems is investigated. In particular, we use a blind version of the partial-bit DS/CDMA receiver to successfully suppress narrow-band and nearfar multiple-access interference without requiring knowledge of other users’ spreading codes, timing or phase information. P...

We study the coexistence of IEEE 802.11b and Bluetooth, and more specifically the performance gains obtained using a frequency domain Bluetooth interference suppression scheme at the IEEE 802.11b physical layer. Focus is on the reduction of packet error rates in heavily interfered environments. The frequency domain structure of the signals is utilised to separate multiple interferers, thereby s...

We propose a two-stage adaptive filtering process for canceling narrowband interference from a wideband signal process, based on a reference signal consisting of a Doppler shifted version of the interference. The first stage uses the timevarying behavior of NLMS with large step-size to produce an estimate of the interference signal, in which the Doppler shift is mitigated. The second stage uses...

This paper deals with the problem of blind interference suppression in Direct-Sequence Code Division Multiple Access (DS/CDMA) channels. We investigate the incorporation of linear constraints to the Constant Modulus (CM) criterion to obtain a new blind adaptive receiver that only requires chip synchronization and acquisition of the desired user code. An analysis is presented that shows how line...

In this paper, a novel robust noncoherent receiver for MMSE interference suppression for DS–CDMA is proposed. The receiver consists of an MMSE filter and a decision–feedback differential detector (DF–DD). The performance of the proposed scheme is investigated analytically and by computer simulations. It is shown that the loss compared to coherent MMSE interference suppression is limited and can...

We present results of adaptive canceller experiments at the Rapid Prototyping Array which compare the quality of interference suppression achieved in the voltage and power domains. It is shown that if the optimal complex weights used to model the interference are stationary over the length of the time average, then the same level of suppression is achieved. A limitation of both methods is that ...

The conventional approaches to enhance the narrow-band interference of spread spectrum systems mostly use the adaptive LMS filter to predict the narrow-band interference and subtract the predicted interfering signal from the polluted received signal before de-spreading. However, since these approaches take no account of complexity control and have no guarantee of global minimum, they often suff...