Because of the unique architecture of wireless receivers, a designer must understand both the high frequency aspects as well as the low-frequency analog considerations for different building blocks of the receiver. The primary goal of this research work is to explore techniques for implementing high performance RF and baseband building blocks for wireless applications. Several novel techniques to improve the performance of analog building blocks are presented. An enhanced technique to couple two LC resonators is presented which does not degrade the loaded quality factor of the resonators which results in an increased dynamic range. A novel technique to automatically tune the quality factor of LC resonators is presented. The proposed scheme is stable and fast and allows programming both the quality factor and amplitude response of the LC filter. To keep the oscillation amplitude of LC VCOs constant and thus achieving a minimum phase noise and a reliable startup, a stable amplitude control loop is presented. The proposed scheme has been also used in a master-slave quality factor tuning of LC filters. An efficient and low-cost architecture for a 3.1GHz-10.6GHz ultra-wide band frequency synthesizer is presented. The proposed scheme is capable of generating 14A novel pseudo-differential transconductance amplifier is presented. The proposed scheme takes advantage of the second-order harmonic available at the output current of pseudo-differential structure to cancel the third-order harmonic distortion. A novel nonlinear function is proposed which inherently removes the third and the fifth order harmonics at its output signal. The proposed nonlinear block is used in a bandpass-based oscillator to generate a highly linear sinusoidal output. Finally, a linearized BiCMOS transconductance amplifier is presented. This transconductance is used to build a third-order linear phase low pass filter with a cut-off frequency of 264MHz for an ultra-wide band receiver. carrier frequencies.

In recent years, the worldwide progress of wireless communication technology has bringing great benefit and convenience to our people¡¦s life. Nowadays, people can use appliances of wireless communication in many fields, such as family-monitoring, automatic system, and smart-type device¡Ketc. However, in order to dealing with the need of low cost and low power communication, the researcher spend many years on developing the specification of IEEE 802.15.4 Low Rate-Wireless Personal Area Network (LR-WPAN) expected be applied in widespread use. In this thesis, we focus on the baseband signal processing for the physical layer specification of the 868/915MHz mode of the IEEE 802.15.4 LR-WPAN. Our design blocks include packet detection, sampling point detection (energy detection), carrier frequency offset (CFO) compensation, carrier phase offset (CPO) compensation, and despreading algorithms. During the process of simulation, we¡¦ll examine whether our design match the criteria of standard such as sensitivity, packet format, and modulation. While our designs achieve the requirement of the standard, we start on quantization. Finally, we¡¦ll realize the algorithm in VHDL and examine it.

Baseband processing is an important and computationally heavy part of modern mobile cellular systems. These systems use specialized hardware that has many digital signal processing cores and hardware accelerators. The algorithms that run on these systems are complexand needs to take advantage of this hardware. Developing software for these systems requires domain knowledge about baseband processing and low level programming on parallel real time systems. This thesis investigates if the programming language Julia can be used to implement algorithms for baseband processing in mobile telephony base stations. If it is possible to use a scientific language like Julia to directly implement programs for the special hardware in the base stations it can reduce lead times and costs. In this thesis a uplink receiver is implemented in Julia. This implementation is written usinga domain specific language. This makes it possible to specify a number of transformations that use the metaprogramming capabilities in Julia to transform the uplink receiver such that it is better suited to execute on the hardware described above. This is achieved by transforming the program such that it consists of functions that either can be executed on single digital signal processing cores or hardware accelerators. It is concluded that Julia seems suited for prototyping baseband processing algorithms. Using metaprogramming to transform a baseband processing algorithm to be better suited for baseband processing hardware is also a feasible approach.

A forward error correction technique known as convolutional coding with Viterbi decoding was explored in this final thesis. This Viterbi project is part of the baseband Error control project at electrical engineering department, Linköping University. In this project, the basic Viterbi decoder behavior model was built and simulated. The convolutional encoder, puncturing, 3 bit soft decision, BPSK and AWGN channel were implemented in MATLAB code. The BER was tested to evaluate the decoding performance. The main issue of this thesis is to implement the RTL level model of Viterbi decoder. With the testing results of behavior model, with minimizing the data path, register size and butterflies in the design, we try to achieve a low silicon cost design. The RTL Viterbi decoder model includes the Branch Metric block, the Add-Compare-Select block, the trace-back block, the decoding block and next state block. With all done, we further understand about the Viterbi decoding algorithm and the DSP implementation methods.

WiMAX provides broadband wireless access and uses OFDM as the underlying modulation technique. In an OFDM based wireless communication system, the channel will distort the transmitted signal and the performance is seriously degraded by synchronization mismatches between the transmitter and receiver. Therefore such systems require extensive digital signal processing of the received signal for retrieval of the transmitted information. In this master thesis, parts of an IEEE 802.16d (WiMAX) receiver have been implemented on a programmable baseband processor. The implemented parts constitute baseband algorithms which compensates for the effects from the channel and synchronization errors. The processor has a new innovative architecture with an instruction set optimized for baseband applications. This report includes theory behind the baseband algorithms as well as a presentation of how they are implemented on the processor. An impartial evaluation of the processor performance with respect to the algorithms used in the reference model is also presented in the report.

As the technology is advances the reduced size of hardware gives rise to an additive 1/f baseband noise. This additive 1/f noise is a system noise generated due to miniaturization of hardware and affects the lower frequencies. Though 1/f noise does not show much effect in wide band channels because of its nature to affect only certain frequencies, 1/f noise becomes a prominent in OFDM communication systems where narrow band channels are used. in this thesis, I study the effects of 1/f noise on the OFDM systems and implement algorithms for estimation and suppression of the noise using Kalman filter. Suppression of the noise is achieved by subtracting the estimated noise from the received noise. I show that the performance of the system is considerably improved by applying the 1/f noise suppression.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents the architecture of a new dynamic multi-protocol network interface implemented on a TT&C satellite baseband processor. Today Ethernet is the main connection of the equipment in a satellite system. Various protocols are necessary to optimize support of data exchange and are implemented using several supports such as Serial lines, Ethernet or Internet. The capability to dynamically switch from one service to another, using the most adapted interface, is the key factor for a multi-mission, multi-satellite system.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Deutsche Telekom is operating various communication satellites since 1989. The SCC (spacecraft control center) is located near Frankfurt / Germany. The entire system is based on antenna/RF equipment, baseband and computer software packages running on a computer network of different machines. Due to increased maintenance effort the old baseband system needed to be replaced. This also had effects to the computer system, especially to the M&C. The aim was to design the entire system in a way that the operation effort in costs aspects and human intervention are minimized. This paper shows the successful real world project of reengineering a traditional spacecraft control center (SCC). It is shown how a fifteen year old hardware (baseband system) and software design was replaced by a modern concept during normal operations. The new software packages execute all necessary tasks for spacecraft- and ground station control. The Monitor and Control System (M&C) is a database driven design (FRAMTEC, from CAM Germany).

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Designers of small airborne FQPSK-B (-B) transmitters face at least two significant challenges. First, many U.S. Department of Defense (DOD) test applications require that transmitters accommodate a continuum of data rates from 1, to at least 20 Mb/s in one design. Another challenge stems from the need to package a high-speed digital baseband signal generator in very close proximity to radio frequency (RF) circuitry required for 1.4 to 2.4 GHz operation. The -B baseband filter options prescribed by Digcom/Feher [2] are a major contributor to variable data rate design challenges. This paper summarizes a study of -B filter alternatives and introduces FQPSK-JR (JR), an alternative to -B that can simplify digital baseband transmitter designs. Very short impulse response digital filters are used to produce essentially the same spectral efficiency and nonlinear amplifier (NLA) compatibility as -B while preserving or improving detection efficiency (DE). In addition, a strategy for eliminating baseband shaping filters is briefly discussed. New signaling wavelets and, modified wavelet versus symbol sequence mapping rules associated with them, can be captured from a wide range of alternative filter designs.

During the thesis, a two-staged analog baseband circuit incorporating a passive analog filter and a wideband voltage amplifier were successfully designed, implemented in an IC mask layout in a 65nm CMOS technology, and joined with a previously designed analog front-end design to form a wideband observation receiver. The baseband circuit is capable of receiving an IF bandwidth up to 990MHz produced by the analog front-end using low-side injection. The final circuit shows high IMD3 of at least 90 dBc. The voltage amplifier delivers a voltage amplification of 15 dB with around 0.08 dB amplitude precision over the bandwidth, while the passive filter is capable of a passband amplitude precision of 0.67 dB over the bandwidth, while effectively suppress signal images created by the mixer with at least 60 dBc. Both stages were realized in an IC mask layout, in addition, the filter layout were simulated using an EM simulator.