Down-link beamforming effects on the code orthogonality in UTRA-FDD systems
نویسندگان
چکیده
A novel approach in quantifying code orthogonality factor for UTRA-FDD systems is extended in this paper to include the impact of down-link beamforming. The effects of fixed beam forming on code orthogonality is analysed through the aid of real channel data taken from urban cellular environments. The results show a significant overall improvement in code orthogonality with beam forming, especially in the case of an urban large cell.
منابع مشابه
Network Performance of Asynchronous UTRA-like FDD/CDMA Systems using Loosely Synchronised Spreading Codes
In this paper we characterize the capacity of a UTRA-like Frquency Division Duplex (FDD) Code Division Multiple Access (CDMA) system employing Loosely Synchronized (LS) spreading codes. Current CDMA systems are interference limited, suffering from Inter-Symbol-Interference (ISI), since the orthogonality of the spreading sequences is destroyed by the channel. They also suffer from MultipleAccess...
متن کاملAdvances in Radio Science Downlink beamforming concepts in UTRA FDD
This article gives a comparison of beamforming concepts. Adaptive beamforming and fixed beam switching in WCDMA-FDD-mode are compared from a system level perspective, ordinary sectorization (three 120 sectors) serves as a basis for comparison. Pilot channels P-CPICH (Primary Common Pilot Channel) and S-CPICH (Secondary CPICH) are considered as additional interference. For adaptive beamforming c...
متن کاملLoosely Synchronized Spreading Code Aided Network Performance of Quasi-Synchronous UTRA-like TDD/CDMA Systems
Figure 1, if BS1 is transmitting and BSo is receiving at the same time in a given timeslot, BS -> BS interference takes In this paper we investigate the achievable capacity of a place, provided that these base stations are in adjacent cells. UTRA-like Time Division Duplex (TDD) Code Division MulIn [3] we demonstrated that the employment of adaptive arrays tiple Access (CDMA) system employing Lo...
متن کاملLoosely synchronised spreading code aided network performance of quasi-synchronous UTRA-like TDD and FDD CDMA systems
It is demonstrated that loosely synchronised (LS) spreading codes exhibit a so-called interference-free window, where both the autocorrelation and cross-correlation of the codes become zero. Therefore LS codes have the promise of mitigating the effects of both inter-symbolinterference and multiple-access-interference in time dispersive channels. Hence, LS codes have the potential of increasing ...
متن کاملSpace-time front-ends for RAKE receivers in the FDD mode of UTRA
A unified and general vision of different space-time processors is presented. Many popular receivers can be accomodated, like V-RAKE receivers, weighted V-RAKE, or spatial narrowband beamforming. By making appropriate assumptions on the space/time characteristic of the interference it is possible to enhance the performance of the receiver through spatial/temporal pre-processors. These receivers...
متن کامل