A baseband Processor must be able to process several different modulation technology, eg. CDMA and OFDM. The processor must be programmatic because wireless standards are changing rapidly such as new modulation scheme are constantly emerging.

There is a need for Multi Standard Baseband Processor capable of processing different wireless carrier standards. The Two traditional CPU architecture that is used or could be used are:

• VLIW(Very Long Instruction Word)

Disadvantage: Low Power Efficiency due to their wide instruction needed to be fetched every clock cycle.

• SIMD(Single Instruction Multiple Data)

Disadvantage: Different Operation cannot be performed concurently

Anders Nilsson proposed a new architecture design for multi-standard baseband processor described below:

SIMT(Single Instruction stream Multiple Tasks) is the new architecture proposal that should increase efficiency. SIMT architecture should have the benefits of VLIW and SIMD in the design.

The SIMT concept has been demonstrated in the BBP1 baseband processor in small scale in Wireless LAN Transceiver. A complete system employing SIMT has been designed in BBP2 baseband processor which has been employed in WiMAX, WCDMA and IEEE 802.11 a/g.

The objective of this research is to find a programmable baseband processor architecture that can process different wireless technologies such as-

• GSM
• WCDMA
• Bluetooth
• GPS
• WiMAX
• Digital TV
• LTE
• Other Multi Media Technologies

The new architecture should have the following constraints:

• Power Efficiency
• Area Efficiency
• Capable of processing multiple radio standards

About Wireless System Processor:

In general a wireless system processor has 3 sub processor as follows:

1. Baseband Processor
2. MAC Processor
3. Application Processor

The funtions of a Baseband Processor are as follows:

• during transmit it facilitates modulation of bits from MAC processor into analog signal performed by the DAC. It facilitates channel coding, modulation and symbol shaping
• during receive it facilitates demodulation of analog into digital bits performed by ADC. It facilitates Filtering, synchronization and gain-control, Demodulation, channel estimation and compensation and Forward Error Corrections.

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