Syed Aon Mujtaba

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The purpose of the cell search algorithm in UMTS is to estimate the spreading code of the serving base-station and its corresponding timing offset. The search procedure consists of 3 sequential and distinct stages: (1) slot-boundary synchronization, (2) frame-boundary synchronization with code-group identification, and (3) scrambling code identification.(More)
In this paper, we propose a simple reduced-complexity decoding technique called bypass decoding for low-density paritycheck (LDPC)-coded multiple-input–multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems. Employing the bypass decoding technique, the receiver of an LDPCcoded MIMO-OFDM system decodes a codeword in two steps based(More)
Polyphase FilterBanks (PFBs) provide a computationally efficient approach to extracting channels of arbitrary bandwidth from a wideband signal. This technique, know as digital downconversion, would find use in software radio applications. Conversely, PFBs can also be used to perform digital upconversion, a process in which a wideband signal is constructed(More)
Beamforming (BF) with multiple receiving antennas significantly improves the bit-error-rate (BER) performance for a DS-CDMA system in a flat Rayleigh fading environment. However, BF fails to suppress multiple access interference (MAI) completely, which results in an irreducible BER floor. Furthermore, softdecision Viterbi decoding (VD) with BF further(More)
A novel scheme for linear Multiuser Detection (MUD) based on Sub-Symbol diversity is presented that is applicable to Asynchronous CDMA systems with frequency selective fading. Traditional solutions for asynchronous linear MUD result in a prohibitively large decorrelation matrix. The new scheme transforms the asynchronous problem into a synchronous one by(More)
A complexity reduction technique for soft-output maximum a posteriori probability detection in wireless multiple-input multiple-output (MIMO) channels using rectangular quadrature amplitude modulation (QAM) constellations is derived. In contrast to existing low-complexity detection schemes that reduce the number of candidate tests, we instead focus on(More)
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