A microcellular local area network (LAN) for indoor communications is proposed using code division multiple access (CDMA) and DPSK for data modulation. The pseudonoise (PN) codes in the transmitters of the base station are mutually synchronized. For this purpose, sets of Gold code sequences having low cross correlation have been found by an exhaustive computer search. Together with wideband mea...

An alternative method to channel estimation is presented as a means of supplying a RAKE receiver with the coefficients for Maximal Ratio Combining (MRC). The proposed RAKE receiver utilizes TimeHopping Pulse Position Modulation (TH-PPM), and is specifically designed to be used in Ultra Wideband (UWB) communication systems in which channel estimation becomes problematic because of the high sampl...

This paper deals with a multiuser cancellation detection scheme combined with antenna arrays, for Wideband Code Division Multiple Access (WCDMA) communication systems where different traffic load and different data rate are considered. The proposed receiver, defined as Space Time-Selective Parallel Interference Cancellation detector, is supposed to be used at the base station of a WCDMA communi...

Transmitted reference (TR) modulation schemes, initially proposed for spread-spectrum systems in the 1920’s have regained popularity in the context of ultra-wideband (UWB) communications, where accurate channel estimation is a challenging task. In the conventional TR approach, a reference signal (without data modulation) is received and employed in a correlator receiver for data modulated signa...

A novel empirical approach is presented for modelling the path loss behaviour of the direct path (DP) between the transmitter and receiver, which is important for time-of-arrival-based indoor geolocation coverage characterisation. Using ultra wideband (UWB) measurements in four sites and three ranging scenarios, pathloss models at 500 MHz and 3 GHz system bandwidths are provided, centred on 4.5...

Manuscript Received 23-October-2012 and revised 16-Janaury-2013 ISSN: 2322-4088 Accepted on daymonth-year Abstract— In this paper, Ultra-wideband (UWB) multiple access relay channel with correlated noises at the relay and receiver is investigated. We obtain outer and inner bounds for the IEEE 802.15.3a UWB multiple access relay channel, and also, a diversity gain bound. Finally, we evaluate som...

This paper introduces the theory of channel modeling for positioning applications in UHF RFID. It explains basic parameters for channel characterization from both the narrowband and wideband point of view. More details are given about ranging and direction finding. Finally, several positioning scenarios are analyzed with channel models developed. All the described models use a degenerate channe...

We report systems for network measurements at millimeter-wave frequencies. Active probes are used for on-wafer measurements to approximately 150 GHz. The active probes incorporate monolithic GaAs mm-wave network analysis circuits (comprising a nonlinear transmission line stimulus signal generator and a directional sampling circuit) and lowloss, rugged quartz coplanar-waveguide probe tips. Wideb...

This paper describes an implementation of the forward link physical layer of the wideband DS-CDMA as described in the preliminary ETSI W-CDMA specification for UMTS [1]. The channel definitions, the frame structure, and the transmission formats for the forward link channels are presented, and the implementation in SPW is described in detail. The description of forward error correction coding an...

In this paper we present the use of an OFDM-based scheme for ultra wideband radios in a multiuser scenario. The proposed scheme uses a technique similar to multicarrier CDMA to allow multiple users to transmit simultaneously to a single receiver. We investigate the performance of the proposed scheme in the presence of both additive white Gaussian noise and narrowband interference, with various ...